Lilith apparently eats babies, according to her helper demon who was trying to get babies out of the maternity ward for her in the Season 4 finale.
Demon king Crowley offers the Leviathan leader Dick Roman a bag of baby uvula muffins to smooth over the alliance he wants to make between their armies. Dick declines, but not on moral grounds; he just considers Crowley a pest to be exterminated. Crowley lets him keep the present.
The demon Abaddon threatens to take over Dean's body and make him kill children and eat infants in Season 9's "Devil May Care."
Angels' true forms. Physically, they (to each other) meet the descriptions of them in religious literature. People look at an angel in his true form have their EYES BURNED OUT. They inhabit human vessels to be able to interact with other humans safely, however. It's notable that they're one of the few, if not only, creatures fitting the definition of an Eldritch Abomination in this series, as the other adversaries are almost all Humanoid Abominations.
Zachariah: My true form has six wings and four faces, one of which is a lion's.
Leviathans and other creatures from Purgatory. They are even referred to by H.P. Lovecraft and by Death himself as the "Old Ones," and Lovecraft was actually killed by one of these things he had been writing about. Their true form happens to be some form of tentacle monster with More Teeth than the Osmond Family. We're never actually shown their true forms, but they can slaughter angels without breaking a sweat.
Later averted as Ruby reveals that Lilith is the first demon, and also whenever Lilith possesses anyone other than a small girl.
Engineered Public Confession: In season 9's Finale, "Do You Believe in Miracles", Cas tricks Metatron into telling his evil mastermind plan on the angel-radar mic.
Enthralling Siren: In "Sex and Violence," there was a gorgeous female siren who worked as a stripper and convinced her clients to kill the women closest to them, usually their wife or elderly, sick mother. She was revealed to be a hideous, melting fish thing whenever seen in a mirror. She also appeared as an attractive male FBI agent to Dean. Make of that what you will.
Epiphany Therapy: Averted. Five-minute self-esteem boosts/pep talks seem to have no effect in the Supernatural!Verse.
Usually epiphanies are learned over days, weeks or even years of grueling fights with monsters and family alike before someone says something that makes Sam or Dean think about something slightly differently.
Sam has one of these featuring Bela, and is very flustered when he figures out who he's been dreaming about (after waking up with an extremely dopey grin on his face). His face wasn't the only thing grinning. No joke; this is actually referenced when Dean calls him over as he's waking up. Sam starts to rise, then glances down and hesitates, using a stretch to cover for his...awkwardness. He's even more flustered and awkward when Bela shows up shortly after to talk with him and Dean.
Dean himself dreams in a later episode of being entertained by two strippers, one in a naughty devil's costume, the other in an angelic one. Kind of tragic, considering Dean is basically soothing his depression from the knowledge that both Heaven and Hell are engaging in the Apocalypse with an escapist fantasy. When Anna drops in, she says she didn't expect his dreams to be like this, and Dean is embarrassed.
Eternal Love: Don and Maggie Stark, powerful witches who have been together for centuries, feature in a Season 7 episode. They've been fighting, and ordinary people get caught in the crossfire.
We learn in Season 8 that, in human life, Crowley's mother was a witch. He speaks of her in passing, but she did pass some of her magical knowledge on to him (which also explains how he came in contact with demons before becoming one himself), implying a close bond.
Even Evil Has Loved Ones: The show seems to love playing with this trope. In some cases, the monsters are monsters BECAUSE of what happened to their loved ones previously at the hands of other monsters or hunters, and some actually form close-knit "families."
It's implied that the demon Ruby had grown to like Sam and exspected him to be rewarded by Lucifer after he unwillingly freed him, though it doesn't stop her for being a manipulative bitch and killed by the brothers.
Pestilence is hinted to have some affection for the demon accompanying him when he hugs her. He also cares a great deal about his "brothers," the other Horsemen. He's royally pissed off at Sam and Dean for taking two of them out before they got to him and plans to torture him gruesomely as payback.
Lucifer wants to wipe out all humanity and the demons and turn Earth into his own pristine Paradise. He does show affection for angels, though, especially his three direct brothers, the other Archangels. He begs his younger brother Gabriel not to turn against him and is on the verge of crying when he has to kill him. His reunion with Michael is filled with mutual regret over what happened in the past and Lucifer again tries to convince his older brother to stop fighting each other. Subverted when Gabriel and Michael both point out that he loves himself even more and is only going on a petty temper tantrum against God for creating humans, although his affection for his brothers appears genuine.
Subverted when it's discovered the demon Crowley had a son, Gavin, whom Bobby was sure could be used as leverage against him. Turns out they both despise each other. Crowley basically proclaims he couldn't care less what Bobby does to Gavin and that he would even relish the idea of him tormenting his soul. His son then gets him back by betraying the location of Crowley's bones in hopes that the Brothers Winchester could burn them. Double Subverted even later on when Crowley becomes more human after a botched demon cure was performed on him. Abaddon kidnaps Gavin from the past and tortures him in front of his father, leading to Crowley caving in to her demands and admitting he genuinely loves Gavin. After Abaddon's defeat, Crowley saves Gavin from dying an early death in the past and provides him with a new home in the present as a farewell gift.
Everybody Lives: Rare in the show since at least one victim appears in each episodes and the brothers have to kill the Monster of the Week. However five episodes manage to keep everybody alive:
"Home" (1x9): The ghost is exorcised before it kills anyone.
"Mystery Spot(3x10)": Dean is killed 102 times by only the the Trickster's reality.
"Wishful Thinking"(4x8): Everything goes back to normal after the curse is reversed.
"The Monster At The End Of The Book"(4x18): Lilith escapes before the heroes come to kill her.
"When the Levee Breaks" (4x21): Much of the episode is spent with Sam tryng to escape a vault.
Crowley is disgusted when one of his allies betrays a temporary alliance they made to cut him out of their deal completely and gives him the option of dying or fleeing, despite all the help that Crowley provided to accomplish their goal. Crowley notes that not even he would commit such a blatant backstab (or rather, frontstab, since the betrayer announces his intentions upfront).
Balthazaar is a rogue, hedonist angel who takes up the demons' hobby of making deals with humans for their souls. However, when he learns that his part-time employer and friend Castiel is working with Crowley to locate Purgatory and take control of its souls, he's so horrified that he switches sides and teams up with the Winchesters to stop them. This ends up costing him.
Evil Albino: Anderson in the Rising Son comics, who has a similar (very negative) opinion of Sam as Gordon in the main series (despite the fact that the comics take place several years before Sam's powers surface).
Ruby was the only demon who had so far actually helped the Winchesters, yet the Season 4 finale showed us that she was working for Lucifer all along and helped Sam specifically for him to kill Lilith, and so bring back Lucifer to Earth.
In the episode "Repo Man." Back when they were hunting Lilith, Sam and Dean exorcised a demon out of a man named Jeffrey. In Season 7, women were dying in the same way the demon killed them back then, so the brothers return to town. It turns out Jeffrey and the demon were working together and had a relationship.
In the finale of Season 8, it turns out that the angel Metatron, who advised the brothers on the last trial to seal Hell and was guiding Castiel in another set of trials to seal off the corrupted Heaven, was not as harmless as he appeared—he didn't warn the Winchesters that completing their trials would kill Sam, and the trials he was helping Castiel with were actually components of a spell to banish all angels from Heaven as petty revenge for being forced to leave Heaven himself.
Evil Cannot Comprehend Good: Averted most of the time. A majority of villains seem to be fully aware that the best way to manipulate somebody is to threaten their loved ones and/or other innocent people.
Demons essentially consider this standard practice.
The angels take a little longer to figure this one out, especially when the good guy is one of them (e.g. Castiel). They take a crack at brainwashing him to re-align his loyalty to Heaven rather than to the Winchesters'. It doesn't stick.
Naomi fully recognizes that Castiel's loyalty to Dean is absolute, and that even under Mind Control he might not be able to betray him. So she subjects Castiel to a lengthy series of VirtualTrainingSimulations in which he has to kill clones of Dean dozens of times until she is satisfied that he will be able to do it for real. But when actually forced to face Dean, he pleads with Naomi, who decides to take direct control of Jimmy (Castiel's vessel) and mercilessly beat a pleading Dean to death because she knows he can't kill him. She doesn't count on the angel tablet she sent Cas to fetch being able to free him of her control, though...
Evil Elevator: In Season 4's "It's a Terrible Life," a security guard gets killed by a malfunctioning elevator in a haunted office building.
Evil Gloating: Demons are the only type of evil at first the brothers face who pull this one. Occasionally some other malevolent beastie will indulge but every single demon does it when most creatures just get right to the killing, or at least attempted killing, of the brothers.
The demons usually use their gloating to mess with Sam or Dean's head and shake them up, either by telling them horrible truths or lies which could be real or playing on their own insecurities. The higher-ups are all REALLY good at this.
In the first season finale, Azazel/YED does this. Dean lampshades it with "Just kill us, 'cuz I just can't take the monologuing." This just fuels Azazel's Breaking Speech.
Brady, in particular, gives one of the most disgusting ones in "The Devil You Know." While tied up, he gloatingly tells Sam how he manipulated him by possessing his friend back in college, and how much he enjoyed burning his girlfriend Jessica alive, setting Sam on the path to going back to hunting. It's so effective that Sam almost ruins the plan by killing him.
Lucifer in particular is either gloating to his enemies or trying to use More Than Mind Control on people he wants/needs to be on his side.
Noticeably, Dick Roman refrains from this completely.
Evil Is Deathly Cold: Demonic and ghostly activity often causes a sudden localized drop in temperature. Lucifer shows this trope by freezing a window with his breath, and states "Sorry if it's a bit chilly. Most people think I burn hot. It's actually quite the opposite."
A Shout-Out to The Divine Comedy where the lowest level of Hell, reserved for the worst of the worst sinners, is actually deathly cold.
As Season 5 goes on, more and more characters start to point out that, for all his wisdom and power, in trying to bring on the Apocalypse, Lucifer is being little more than a bratty child throwing a tantrum because he didn't get a second serving of ice cream. He doesn't listen.
Zachariah goes to the trouble of making a fake Mary Winchester, just so he can make out with her to Squick Dean and Sam. He even proudly tells them, as he's doing it, that he's petty. Tellingly, Supernatural is one of the few places you can see an angel refer to someone as a MILF.
Oddly enough, despite his status as a Reasonable Authority Figure, Death casually kills a man for bumping into him and not apologizing shortly before ranting about how annoying it is being made to do Lucifer's petty bidding.
Evil Is Sexy: The tagline of the show is "Scary just got Sexy!"invoked.
Evil Mentor: The demons usually take up this role towards the heroes.
The Yellow-Eyed Demon, Azazel, fancied himself this and sort of managed it, in a ham-handed way, with the rest of his specials, but Sam has a personal grudge and Heroic Willpower and a big brother, so it never really worked. Ruby's the follow-up.
Ruby, even if her intentions are good. She spends a season being mysterious and helpful before Dean dies, and then provides the bereaved Sam with emotional support and encourages him to develop his Psychic Powers, which are of demonic origin, in order to avenge Dean. Even though he'd promised Dean he wouldn't use them. She gets him hooked on demon blood, a power booster that turns out to be highly addictive as well as revolting, and ultimately uses him to free Lucifer. She was Lilith's inside woman all along. Even though he showed a lot of The Dark Side Will Make You Forget markers, Sam never got further than rather lukewarm Well-Intentioned Extremist...unless he actually exsanguinated that poor nurse Cindy, but that was a once-off. He trespasses rather badly against his family, but almost all of it is either under siren venom or in the throes of withdrawal. Sam is actually a really good guy, but no one including Sam really believes that even a little for much of Season 5.
Alastair to Dean. When Dean was in Hell, Alastair tortured Dean for decades until he broke completely, and then taught him the arts of torture so his student could apply his teachings on the new arrivals. Plays up the avuncular thing kind of the way Azazel used to. Thankfully no signs of Stockholm Syndrome—at least not that survived his resurrection.
Lucifer toyed with the role as well. These idiots will not leave Sam alone. On the other hand, Soulless Sam in Season 8 didn't need Samuel's influence to be a cold sonuvabitch.
Crowley to Cas in Season 6, a bit. Not that the latter isn't the more powerful, but the former leads him by the nose with the hope of knowledge he can use to end the war in Heaven, and his partnership with the devil's replacement drags him down until the Moral Event Horizon makes a faint whooshing sound as it flies by. Somewhere around the time he started killing his friends so they couldn't stop him, maybe? And then he succeeds and goes batshit insane.
In the eighth season episode "Freaks and Geeks," Victor Rogers takes in three orphaned teenagers and trains them to hunt the sort of monsters that killed their families. If that was all he did, it would be downright heartwarming by Supernatural's standards. Unfortunately, he's also the one who arranged their families' murders in the first place and had innocent people turned to play the part of the villains for the Roaring Rampage of Revenge.
Evil Versus Evil: Season 6 ends up using this trope by the end. In order to stop Raphael from restarting the Apocalypse, Castielallies with Crowley to gain control of Purgatory's souls. Crowley and Castiel start hunting down monsters to find it, which pisses off the progenitor of every monster on Earth and prompts her to come down and destroy them and humanity in the process. The Mother of All is killed early in the run, leaving the other three. Castiel eventually jumps off the slippery slope and decides to become the new God, so he cuts Crowley out of the deal. Which causes Crowley to, in turn, ally with Raphael against him. Castiel outwits them and becomes the new Lord.
Let's be honest, the angels are pretty darn evil, killing and possessing human nearly as often as the demons.
In Season 5, Crowley—a powerful, successful and very evil demon—helps the brothers to combat Lucifer and the world-shattering threat of the Apocalypse, as he's quite enjoying himself.
In Season 7, Crowley does this again, as the Leviathans are organizing the wholesale slaughter of mankind, every other monster race besides themselves, and threaten to destroy the demons if they weren't occupied elsewhere. Over the course of the season, he subtly aids the Winchesters to find a means to kill the Levi leader and destroy their army.
Season 1 is full of bits which are lifted from The Ring. Examples include the boy scrawling a black circle endlessly until it's a pitch black well in 01X03, the water flowing down the stairs when the mother killed the children by drowning in 01x01, the girl crawling out of the mirror (complete with jittery effect) in 01x05. The writers must really have loved that film. 01x04 also has the bathtub water going black, just like The Grudge.
The Reaper named Tessa is an Expy of Death from The Sandman.
"Frontierland" borrows a lot from Back to the Future Part III. Dean goes by "Clint Eastwood." He and Sam get costumes which the locals make fun of. Sam gets a package from Samuel Colt over a hundred years later, and the guy who delivers it says everyone at the post office has been wondering if Sam would actually be there to receive it, etc.
The angel Balthazar is an Expy of Gabriel who was killed in Season 5. Prior to Season 6, the producers confirmed that he would return in one way or another, they just didn't know in what way yet. This is how.
The demon Crowley is an Expy of, er, the demon Crowley from Good Omens, himself named after occultist Aleister Crowley. Fanfiction writers have been known to make use of this, though as time goes on, the similarities between Supernatural-Crowley and Good Omens-Crowley are becoming fewer and farther between.
The Colt is an Expy of the Ace of Winchesters, an all-killing gun from Hellblazer.
The Fair Folk: As of Season 6, fairies officially exist. Considering that the gods of all the major religions have already been shown to exist, this isn't so much a surprise, but it does confirm that there are different kinds of magic, particularly Wild Magic, which plays differently into the whole angels and demons power struggle.
Faking Amnesia: Dean fakes a case of Death Amnesia after being pulled out of Hell by Castiel. It's possible it's actually true at first, but by an episode or two later, he's blatantly lying.
Fallen Angel: Fallen angels are angels who have been cut off from Heaven; the resulting affect on angels varies depending on how high said angels are on the celestial hierarchy. Their reason may range from simple AWOL to full-on rebellion, but all of them inevitably land themselves a spot on Heaven's Most Wanted List, so each individual fallen angel come up with ways to evade the armies of Heaven.
Anna, knowing this, cut her angelic energy (called "grace") out when she left Heaven. Reborn as a human, it was nearly impossible for the Heavenly Host to find her among the billions of people on Earth. Even after she regained her Grace, she remains a fallen angel, as she was never seen using an ability that required a connection to Heaven on-screen.
Castiel is probably the more traditional fallen angel, slowly losing his powers throughout Season 5.
Balthazar's defection might eventually result in him running into this problem as well, so he keeps himself charged with human souls.
For seraphs, even after severing ties with Heaven, they still keep all of their abilities. And though they can be exhausted when over-using their power, their angelic energy can be self-replenished with rest.
Castiel in late Season 7 and Season 8 is a fallen seraph. He is clearly weakened by his time in Purgatory probably due to over-taxing himself in Monster Land, but soon self-recharged after his release.
For Archangels, being cut off will have absolutely no effect on them. They will keep all their abilities, complete with an unlimited self-sustained power source to boot.
Lucifer, of course, is a fallen Archangel. The demons of this setting are all derived from human souls; if Lucifer took any other angels with him when he left, they go unmentioned and are apparently dead now. If any demons are former angels, they are most likely all drained of their angelic powers long ago, became human, then damned in Hell due to not being high enough on the angelic food chain.
Gabriel. The reason he can skip out of Heaven and keep all his abilities is because he is an Archangel.
Family of Choice: Dean and Sam had a rough start to life, with their father raising them on the road after their mother was killed by a demon. Their father's obsession with the demon led him to make often-unrealistic demands of the boys, but family friend Bobby did his best to let them be kids whenever Sam and Dean stayed with him. The brothers consider Bobby family and he tells Dean (in the Season 3 finale): "Family don't end with blood, boy." In the Season 7 episode "Death's Door," Bobby says:
Bobby: I adopted two boys, and they grew up great. They grew up heroes.
In "Skin," the Skinchanger in Dean's form takes his shirt off. Then he peels off his skin next.
In "Sex and Violence," the Siren has sex with one of its victims. It's taken on the form of a beautiful woman, but when the camera pans over to a mirror reflection, it looks more like a rotting corpse.
In "My Bloody Valentine," a couple begin making out. Then she takes a bite out of him, and he takes a bite out of her; they eventually eat each other to death.
In "Point of No Return," Castiel takes off his shirt, but he carved an angel-banishing sigil into his chest beforehand.
In "Meet the New Boss," Castiel unbuttons his shirt while standing in front of a mirror, but his body then deforms as the Leviathans he is hosting try to break out.
Fanservice: The first episode had a ghost with more cleavage than you could shake a stick at. The trend continued. Even the brothers themselves are Fanservice. Heck, in sex scenes, the camera looks at them more than their partners, as a rule.
Fantastic Aesop: "After School Special" brings us this—Don't assume that just because somebody acts like a jerk, they don't have problems of their own. And besides, if you do lash out at them, they might get so angry they'll come Back from the Dead for revenge.
Fantasy Kitchen Sink: The monsters in the show all fit an urban myth feeling, until they started incorporating all kinds of mythology, no matter how much of a square peg, round hole it was. There are ghosts, demons, angels, gods, zombies, fairies, vampires, werewolves, witches, wendigo, extra-dimensional monsters, possessed trucks, a Frankenstein-style Mad Scientist who is effectively immortal through the theft of new organs, and many more. In "Hammer of the Gods," various pantheons from around the world sent representatives in a meeting to discuss ways to stop the Judeo-Christian Apocalypse. Attendees included Odin, Mercury, Kali, Baldur and Ganesh, to name a few. So far no aliens, though. This was lampshaded a bit when one of the brothers said that everyone knew there was no such thing as Bigfoot. Bobby can usually find info on new monsters, after the writers let up on the use of John Winchester's diary. At some point, Team Winchester realized they were dealing with monsters that were entirely unprecedented.
The Farmer And The Viper: In the first episode, a ghost is killing men who see her hitchhiking and pick her up. The trope is arguably averted because her victims have an ulterior motive—she is smoking hot and the drivers are hoping the pickup turns into a hookup.
Fate Worse than Death: In Hell, you're basically tortured, daily, in unimaginable ways, for decades on end, unless you agree to do the same to others. Dean held out for thirty years.
The end of season five had Sam stuck in hell's solitary confinement with vengeful archangels Fallen AngelLucifer and Michael torturing him creatively for a hundred and eighty years or so.
"Bibbing" for Leviathans. Made worse since if they don't eat themselves fast enough, they'll simply regenerate and have to start all over again.
Alastair aka Picasso with a Razor loves to smile and chat up his victims as he's carving them up. He also inverts the trope in the episode "On the Head of a Pin", when he becomes Dean's torturee and spends the whole time dispensing advice, commenting on Dean's technique, or reminiscing about the good ol' days back in Hell, when he apprenticed Dean in the arts of mutilating people.
Lucifer is another prime example. Apparently, being locked in a Hell cage for a few millennia works up an appetite for conversation. He treats Sam with affection, and never insults his victims or even raises his voice. But, despite his charm, he's squarely in the Faux Affably Evil camp because... well... he's the devil and stuff... In the season 5 finale "Swan Song", Dean finally manages to annoy him too much. He drops the act and shows just how affable he really is.
Crowley is presented as an Affably EvilNoble Demon in series five, but season six reveals that he's more Faux Affably Evil, as he starts getting more and more into torture. He's obsessed with bargains (as befits his "king of the crossroads" status) but will take on any persona which will get the job done.
Dick Roman, the leader of the Leviathans. Having stolen the identity of a billionaire businessman, he likes to talk in a friendly, forward thinking fashion while planning the enslavement of mankind. Best exemplified by him talking to a subordinate about turning his failure into a "teachable moment" by making him eat himself.
Feud Episode: One "Rashomon"-Style episode deals with the brothers fighting, which, as Sam pointed out, is understandable for two guys who spend all their time cooped up in a car together. Bobby is not amused.
Generally happens quite a lot. Sam and Dean have, morethanonce, gotten so pissed off at each other that they go their separate ways for an episode or two, only to inevitably reunite a couple weeks later. Dean and Cas have also spent a coupleepisodes with one angry at the other.
In the Season 1 finale "Devil's Trap", John resists possession and gives his son a chance to kill YED.
In Season 5, Bobby successfully fights off possession by one of Meg's henchmen long enough to stab and cripple himself with a demon-killing knife so he didn't kill Dean.
Deliberately invoking this trope is how Sam takes down Lucifer at the end of season five.
Final First Hug: Sam and Dean would die for each other, have killed for each other, would sell their soul for each other, but the first time they hug is at the end of season two, when Sam's just been stabbed in the back and dies in Dean's arms.
Fire and Brimstone Hell: Played with. To sum it up, a demon describes Dante's take on Hell as "a bit of an understatement."
This is the main reasoning behind a "hunter's funeral." Hunters burn the bodies of other hunters killed on the job so that they can't be turned into zombies, resurrected as vengeful spirits, animated by demons, or tampered with by some other supernatural means.
"Salt and burn the body" is the standard solution to malevolent spirits and such. If the body's already been cremated, the boys need to find an alternate solution. Sometimes this means finding the little bit of the body that wasn't burned and setting fire to it.
Flanderization: Dean going from very flirt-happy to being a man-whore extraordinaire.
And while he was never really seen as a good father anyway, John seems to be getting more despicable every time they mention him.
Castiel seems to be getting more socially clueless over the years, despite the fact that he observed humans for centuries and now interacts with them regularly.
Flat Earth Atheist: John and Dean, with Dean being the primary example. While he very easily believes in the supernatural (hence the name of the show) and Hell, he simply flat-out refuses to believe in things like angels, Heaven, and God."Gods" are simply very powerful monsters, but you can still "gank" them. Dean is forced to face his lack of belief after he returns from Hell, when faced with the angel Castiel. Cas becomes a regular on the show, as does their "prophet" Chuck. Even the demons (re: Lucifer) end up stressing the fact that God exists—He might not be there, but He does exist. Lucifer goes on this long-winded schpiel about his devotion to his Father (God) being the reason for his falling from Heaven. Dean, while eventually admitting to the fact that God exists, never fails to ruffle the feathers of all the angels he comes across, simply for the fact that they are, as he puts it, "dicks." This is where at least 60% of the humor from season 5 onward comes from, still managing to question the core accuracy of the Bible, or just religion in general.
Inverted when the forced feeding wasn't the torture, but the cure to torture: Dean is writhing in agony on the floor coughing up blood due to a hex when Ruby busts down the door and bodily hurls him onto the bed before forcing a potion down his throat, breaking the hex and saving his life.
Dean tortures Alastair in "On the Head of a Pin" by pouring a whole bag of salt in his mouth.
Flies Equals Evil: Pestilence is constantly surrounded by flies. Justified, since flies are vectors of disease.
Forgotten Fallen Friend: Adam Milligan, the third Winchester brother, who was last seen in "Swan Song" being thrown into Lucifer's Cage while serving as the host of the Archangel Michael. While Sam was likewise thrown in, being the host of Lucifer at the time, after he was rescued, both him and Dean don't really bother trying to find some way of getting Adam out as well. In "Appointment In Samarra" Dean does ask Death to save Adam's soul, only to be told he can't have both. Of course, he chooses Sam. So it really is implied that Adam will spend the rest of eternity as Lucifer and Michael's punching bag.
Dean's guilt in "Faith" being ramped up to 1000 when John dies for him in Season Two, Dean wanting to make a Deal with the Devil to get his father back in "Crossroad Blues" and actually doing so (except for his brother this time) in "All Hell Breaks Loose", all of Dean's onscreen deaths (7 in total?) leading up to the big one in "No Rest For The Wicked" and Dean's "All things considered" comment about their childhood in "Nightmare" turning out to be unbelievably loaded.
Sam and Dean's relationship to their father in Season 1 is incredibly similar to Lucifer and Michael's to God. This is, ah, occasionally noted, by them and others.
Several episodes have Sam and Dean fighting each other (well, kind of, thanks to demonic possession, hallucination, shapeshifter...). In the fifth season, we learn that as the vessels of Lucifer and Michael, they are destined to fight each other.
In the third season premiere, Ruby pulls a Stealth Hi/Bye while tailing Sam, and is recognized by one of the demons she kills ("You!") when said demons haven't been topside in centuries. The next episode reveals that she is a demon.
The following conversation in "Point of No Return":
Sam: There's another way.
Adam: Great. What is it?
Dean: (sarcastically) Well, we're working on the Power of Love.
Adam: How's that going?
Dean: Not good.
In the end, it's pretty much exactly the power of love that saves the world.
Christian taunts Dean for having tortured people in Hell. While Dean and the viewers assume that Sam mentioned it to Christian in the year they spent together before the Season 6 premiere, we find out later that Christian has been possessed the whole time, so he probably knew it already.
During Season 5, everyone else thought Lucifer just a bratty child who was having a tantrum. It comes to a head when the demon Crowley talks with Castiel in a flashback in "The Man Who Would Be King" and says, "Lucifer was a petulant child with daddy issues," accurately describing Castiel's current Character Development. With his current status as Rebel Leader, it looks like he's about to become the next Lucifer.
Worse; it foreshadowed Cas declaring himself the new God.
Season 1, Episode 6
Dean: I tell you though, I'm sorry I'm going to miss it.
Dean: How many chances am I going to get to see my own funeral?
Played with the Crossroads Demon, who almost always takes form of a sexually appealing woman. Considering that the demon seals her Faustian deals with a kiss, this probably plays into her advantage. Same goes for Lilith. Subverted in later episodes. The demons will appear in whatever body they've decided to possess, and they don't always pick a body that is sexually appealing. Crowley in particular didn't, and still expected his client to seal the deal with a kiss, much to the (male) client's disgust.
In addition, angels have to possess human "vessels" in order to interact with humans, because seeing an angel's true form will burn out a person's eyes and its true voice causes shattered glass and bleeding ears. Castiel eventually reveals his true form is "about the size of your Chrysler Building." Which raises the question of why Lucifer and Michael even needed human vessels to begin with, since neither of them seem to care whether or not they harmed humans. Fighting each other in their true forms would have saved a lot of time and effort, as opposed to spending a season trying to coerce Sam and Dean into becoming their vessels. The only answer given so far is "Them's the rules." They're required to have a host, but we don't know why precisely.
It's implied that Angels and Demons cannot walk the Earth without a human vessel (we have never seen either do so, demons exist only as black smoke without a vessel), and since Earth and humanity are fairly disposable to Michael and Lucifer, it makes sense that they'd rather fight here than in Heaven or Hell, which could be equally decimated by the combat.
Played straight in Dark Side of the Moon when the brothers visit Heaven. While there, the garden at the center of Heaven will change its appearance according to what the viewer most expects it to look like, becoming the botanical gardens in Cleveland for Sam and Dean. Also, angels still appear human and wingless, which is even lampshaded by Zachariah:
Zachariah: In Heaven I have six wings and four faces, one of which is a lion. You see this because you're... limited.
In later seasons after his angelhood is restored by God, Castiel has several conversations in Heaven with other angels, while no humans or other "limited" beings are around. They still appear as their human vessels.
This is probably just a convenient (and cheaper) way to represent them so that the audience will recognize who is who.
Reapers also tend to appear in the form of a human to the recently deceased, such as Tessa appearing to Dean as an attractive young woman when her true form proved rather frightening to him.
Dean: You sure are a lot prettier than the last reaper I saw. Tessa: You saw my true form and flipped out. It kinda hurts a girl's feelings.
In a later episode, the ghost of a young boy was frightened of even Tessa's human form, until on Dean's advice, she changed her denim and leather outfit into a cute white dress.
Zachariah: We didn't lie, we just avoided certain truths to manipulate you.
From Bad to Worse: Pretty much the only thing that has ever gotten better is Sam's guilt over Jess dying. And that's just because he has had much more pressing issues to deal with lately.
"Meet the New Boss" could have been called "How Can the Situation Get Worse." OK, Castiel is now a God. Not too bad at first; he's not going to kill the Winchesters and Bobby. OK, killing hypocrites and leaders of other religions is a bit much, but he does get rid of the Ku Klux Klan. After 200 deaths, he seems to become an Omnicidal Maniac, killing people for the fun of it (if his Slasher Smile is anything to go by). Finally, he gets possessed by the Leviathans, who proceed to go "This is going to be so... much... fun..."
The latest season finale... Thanks to Metatron? There are no more angels, permanently forcing them from Heaven. Thus the power has shifted COMPLETELY to Hell.
Genre Blindness: Played for Laughs. One of the boys, usually Dean, constantly speculates that the events have a mundane explanation in spite of events almost never going that route.
Genre Roulette: Pick a week, load in a bullet, and spin to see where the Mood Whiplash lands. Some serious Out Of Genre Experiences occur, however they're all done very well, so the emotional and psychological continuity is generally preserved in the long run. Every variation on the horror genre is done, of course. Also plenty action-adventure genre. Comedy and parody feature heavily. You can also throw in slice-of-life, surrealistic Mind Screw, and philosophical debate on the nature of life, death and the human soul, a dash of romantic tragedy, and your occasional fantasy adventure-land and/or alternate dimension.
Geometric Magic: Sigils and wards are the most effective means of constraining beings like demons and angels. Hunters use it often. Demons and angels even frequently use it against each other. However, it turns out that Metatron, as the Scribe of God, has the power to erase such things at will, even those that would normally impede an angel such as himself.
In fourth season episode "Heaven and Hell", Dean is given an ultimatum by Uriel—to hand Anna over to die, or go back to Hell. He initially doesn't think that Uriel do it, but once convinced he will, still tells him to go ahead, much to Uriel's surprise. He switches to threatening Sam instead, and this time Dean complies, exactly as Sam had planned.
In the season 5 episode "Dark Side of the Moon," Dean is sitting in his hotel room at gunpoint as Roy and Walt argue over whether or not to kill him. He finally growls, "Go ahead, Roy, do it. But I'm gonna warn ya—when I come back, I'm gonna be pissed." This can be viewed as a variation on the trope because Dean knew Zachariah would just resurrect him anyway.
In "The Devil You Know", Crowley asks "fancy a fag and a chat?". Crowley's British (specifically, from Scotland (despite his more English-sounding accent), as Bobby discovers when digging up dirt on his life before he became a demon), so he "means" a cigarette, but he's a in-canon Ho Yay figure in an American show devilishly sliding in a hidden reference.
In "Yellow Fever," there's a brief mention of a pair of softball teams, the Gamecocks and Cornjerkers.
In "Season 7, Time for a Wedding!", Becky ties Sam up and shoves a gag in his mouth when the Love Potionshe's been slipping him wears off. He shouts "Fuck you!" at her, but she misunderstands because of the gag and chirps back, "Love you, too!" Evidently everyone else misunderstood, too, since it made it to air. Probably the only time Supernatural will get away with saying "fuck" on The CW.
The show loves working Dick Roman's first name into just about every mention of him and often goes out of its way to be totally immature about it, from "THE RISE OF DICK" to gems like:
Newscaster: Why is Dick...so hard to beat?
Ghostapo: Apparently, the Nazis studied magic during WWII. They formed necromancers who could raise the dead.
Ghostly Chill: Cold spots indicate past or impending ghostly hijinx.
Gilded Cage: In the season 4 finale, Zachariah and the other angels detain Dean in one of these to keep him from getting himself killed since he's one of the only people suitable to host the Archangel Michael and to prevent him from stopping Lucifer's escape. It's a lavish and opulent room stocked with Dean's favorite beer and the best burgers he remembers eating from his childhood; the angels even offer him Ginger and Mary Ann from Gilligan's Island because Dean has always had a thing for them, but he passes. In a moment of helpless despair, Dean almost gives in and tries to drink one of the beers right before Castiel breaks him out.
Gilligan Cut: From 6.07 "Family Matters", as Dean wants to get involved in the hunt on the Alpha Vampire:
Dean: [to Samuel]: Big Daddy bloodsucker? I ain't gonna miss that. But this is your deal, I get it. I'll follow your lead. I trust you.
Dean: [outside] I don't trust him.
Girl of the Week: Now, come on, are we ever going to see Cassie or Sarah again? It seems every three episodes Dean or Sam meet a girl who they kiss and promise to visit again soon. Nope. (But we do see Sarah again, way later in Season 8!—when she gets killed by Crowley to screw with Sam and Dean.) Mostly applies to the first few seasons, since the writers soon start trying to create recurring female characters to give Sam and Dean more stable Love Interests. Though this also has the problem of the characters being disliked by fans and thus axed by writers, and the writers start placing a lot more emphasis on the male main characters' bonds, limiting the screen-time and potential a female character has to bond with a Winchester.
Castiel as of the season 6 finale, wherein he absorbs all the souls of Purgatory into himself. He proceeds to do to Raphael exactlywhat Lucifer once did to him, shrug off a Back Stab with an angel-killing dagger, and declare himself the new Lord.
"I'm not an angel anymore. I'm your new God. A better one. So you will bow down and profess your love unto me, your Lord...or I shall destroy you."
When the brothers first meet Chuck, and prove to him that they are indeed the characters he has been writing about, his immediate reaction is this trope. The brothers didn't believe him, and he turns out to be a Prophet. At the end of the following season, it's implied that he actually IS God.
Chuck: Well, there's only one explanation. Obviously I'm a god.
Sam: You're not a god.
Chuck: How else do you explain it? I write things and then they come to life? Yeah, no, I'm deinitely a god. A cruel, cruel, capricious god. The things I've put you through ...
God Is Dead: Or so it seems (and a couple different characters claim) until half-way through season five. See next several points below.
Judeo-Christian God is either a deadbeat dad that wandered off to do his own thing leaving the kid that likes to murder puppies (the angels) in charge, or, if he's actually the author of the in-universe Supernatural novels, he's actively torturing the protagonists by, among other things, revealing every detail of their lives and work to their numerous enemies, most recently Crowley, who did the obvious and went on a murder spree through the list of folks they'd saved.
God and Satan Are Both Jerks: The Apocalypse boils down to Lucifer and the rest of the angels having daddy issues, and God enabling it all (while being perfectly aware of the fact that it is going on) by simply continuing to avoid his kids. Even Death finds this annoying, especially when Lucifer drags him into the middle of it against his will.
Gods Need Prayer Badly: Both Mordecai the Tulpa in season 1 and the pagan gods throughout the series. While some of the pagan gods have hundreds of millions of followers, the Abrahamic one and his angels don't seem to get their power according to this.
Actually, this would explain the fact that the Abrahamic religions produce plenty of angels and demons (which all of the believers of the various branches agree on to a point) but the actual Abrahamic god either actually doesn't exist or de facto doesn't exist by virtue of wandering off into obscurity or being dead. Even minor factions within the same protestant or Islamic sect can differ broadly on the nature/identity of god and the largest unified faction (Catholics) actively refuse to give him identifying characteristics. Ergo, there's just not enough unified belief in a coherent mythological deity for him to actually exist as such, whereas everyone pretty much agrees on angels being lawful good/lawful stupid people of mass destruction.
Neither do the pagan gods, it seems. They are all not that powerful, regardless of followers, and if they bitch about not having many followers, it seems like missing fame and willing sacrifices.
A strange variation of the Jesus Taboo is in force here. We have seen the goddess Kali and the god Ganesha among the ranks of "pagan" gods. Hinduism is a major world religion with nearly a billion adherents. By all rights the Hindu gods should be serious heavyweights compared to deities whose worship has largely ceased, such as the Norse or Olympian gods if prayer is direct factor in defining the power of a god.
It's likely that it's consistent: either everything is contingent on belief and the Jewish god and his angels win out by virtue of having two major religions feeding them (Christianity and Islam), or no one really needs it magic-wise and it's more of a vanity/political influence thing.
Godzilla Threshold: Several characters think this point has been reached at various times.
By the end of season five, everything has gone so far to hell that having Sam say 'yes' to Lucifer and toss himself back in his cage is the only option. Of course, at the end of season 4, they'd all pretty much realised that they were screwed.
Going Cosmic: Seasons 4, 5, and (to some extent) 6 focused increasingly on the Apocalypse and there have been a number of angels speechifying about the world as they see it, including Lucifer.
Golem: The rabbis of the Judah Initiative made one to fight the Thule Society during World War II. By the modern day it's been bequeathed to a non-observant Jewish guy who doesn't know what to do with it because he never paid attention to his grandfather's teachings. In fact, he used the pages of the instruction manual he was given as wrapping papers for his smokes. The golem is a little ticked off by this, since it is supposed to receive guidance from its rabbi, not the other way around.
Played straight, once Fridge Brilliance sets in: Dean, on the rare occasion he has a sex scene, is shown to be very much a "lover," with deep and romantic engagements. Sam (who may or may not be The Antichrist), on the other hand, fucks, to put it bluntly.
Extended even further with the people they get with. Sam goes down so very dark roads and is the vessel of Lucifer and ends up fucking Ruby, a demon. Dean on the other hand sticks by his principles and his family, is Micheal's vessel and has a one-off with Anna, a fallen angel.
Played even more straight with the Robo!Sam's bathroom scene versus Dean's dream about Lisa comparison.
Good Versus Good: The series addresses this in the second season arc involving Gordon Walker. He is a hunter, a relentless one, but only interested in killing vampires/demons - at first. However he crosses over into Grey or Black Morality, when he doesn't relent from trying to kill a group of vampires who have abstained from feeding and are trying to just live their lives, and it is also implied he kills supernatural creaturs solely out of hate for turning his sister and ruining his life.
Gory Discretion Shot: Might as well be renamed the Supernatural Extra Death Shot, because almost every episode involves a victim of the week biting it with a spray of blood or teddy bear stuffing on something else.
Grand Theft Me: In the episode "Swap Meat", a teenaged boy changes bodies with Sam.
The Grim Reaper: featured a few episodes with a black-haired reaper, who guides the deceased to their afterlives.
Lucifer summons Death himself in Season 5's 'Abandon All Hope'. He is one of the four Horsemen of the Apocalypse and the boss of all reapers. He also claims to be at least as old and as powerful as God, and that in the end, he'll reap Him too. Don't ask how that even works.
Guttural Growler: Dean has become increasingly gruff over the seasons (seriously, listen to season one compared to season six). Castiel, too, is fairly growly, although this is on purpose; actor Misha Collins felt that as Castiel's natural voice shatters windows and makes people's ears bleed, his voice in his human vessel should be rather tough-sounding. (He has also confirmed that he and Jensen Ackles 'compete' during their scenes together to see who can sound growlier, although this may not be literally true.) Bobby could also be considered an offender, as could Crowley...it's pretty much just a cast full of BatVoice.
Dean's growly voice was awesomely lampshaded at least twice: once in "The Real Ghostbusters" when a fan was pretending to be Dean, and once in "The French Mistake" when Jensen was playing Dean playing Jensen playing Dean. ("That's how he does it.")
Jesse is half-demon, having been given birth to by a possessed woman. He looks no different from a normal human, but is described by Castiel as being more powerful than either a human or demon.
Two And A Half Men implies that regular shifters are all the half-human offspring of the alpha shifter.
"Clip Show" introduces the half-human, half-angel Nephilim, considered by Heaven to be an 'abomination'. Castiel and Metatron kill the only one on Earth, a woman named Jane, as part of the trials to close Heaven.
Hannibal Lecture: As he seems to have a neon sign on his forehead saying "self-loathing woobie with Daddy Issues", Dean tends to get this done to him a lot. The Crossroads Demon (twice), The Yellow-Eyed Demon (twice), Sam whenever he's under the influence... The list goes on.
Perhaps the best example of a Hannibal Lecture is the torture/interrogation scene with Dean and Alistair. Supposedly, Dean is extracting information on "who is killing the angels," but not only does Alistair have no idea, he strings Dean along and gives him a thorough mindfuck in between bouts of being eviscerated. The power dynamic in this scene goes back and forth like no other, between Dean relishing Alistair's pain and Alistair breaking Dean down.
The scene in My Bloody Valentine when he corners Famine in a diner is one of the most painful examples on the show:
Famine: Have you wondered why that is? How you can even walk in my presence?
Dean: I like to think it's because of my strength of character.
Famine: I disagree. Yes. I see. That's one deep, dark nothing you've got there, Dean. You can't fill it, can you? Not with food, nor drink; not even with sex. Oh, you can smirk and joke and lie to your brother, lie to yourself, but not to me. I can see inside you, Dean. I can see how broken you are, how defeated; you can't win and you know it, but you just keep trying, just keep going through the motions. You're not hungry, Dean, because inside you're already dead.
A broken one came from Lucifer in the late season 5 episode "Hammer of the Gods" in a speech to Mercury.
Lucifer You know, I never understood you pagans, you're such petty little things. Always fighting, always happy to sell out your own kind. You, are worse than humans. You're worse than demons. And yet you claim to be gods. No wonder you forfeited this planet to us. And they call me prideful.
Done by several Leviathans in 7.06 "Slash Fiction". Bobby mostly shrugs off his double's taunts, but Sam gets hit hard by Leviathan!Dean's revelation.
Hate Plague: The blood-borne Croatoan virus, which makes people violent and crazy.
Heal It With Booze: Sam and Dean have used this method for years. Demonstrated one time when they were Trapped in TV Land on "Dr. Sexy, MD" - Doctor Dean got shot and Doctor Sam had to operate.
"I need a pen knife, some dental floss, a sewing needle, and a fifth of whiskey. Stat!"
Healing Factor: The Leviathans have this as part of their skill-set. Edgar recovered from having a car crush him, and Borax, while capable of hurting them, only causes temporary damage. When they have their heads removed, it reattaches itself.
Gabriel (also known as the Trickster) appears to be this, tormenting others for his entertainment, creating women out of thin air, gorging himself on chocolate and other desserts. Then it's revealed that, although he does enjoy it, he actually means some of the lessons he claims to be trying to teach and seems a little miserable under his Trickster persona.
Then there's Balthazar (funny how all of these are angels). His reaction to the good guys derailing the Apocalypse is to grab a bunch of valuable weapons, fake his own death and start doing whatever the hell he wants on Earth ("This morning I had a menage a...what's the French for twelve?"). When Castiel catches up to him, he insists he's just following the example Cas set. "You showed me we could do anything, so I'm trying everything."
Although Castiel is unarguably trying to be the good guy, he appears to have been trapped in this revolving door since his first appearance. He starts out as the angel that rescued Dean from Hell, but then it's revealed the angels have plans for Dean and expect him to do exactly as they say even when their plans are morally ambiguous to say the least. Castiel starts to have doubts and sympathise with Dean, eventually twisting the rules to help Dean. But then he gets dragged off to Heaven and forced back into line, betraying Anna and setting Sam free to go start the Apocalypse, before he betrays Heaven for good and sides with Dean a couple of episodes later. He spends most of the fifth season on the Face side of things, but appears to have jumped back into the revolving door as of season 6. He makes a deal with Crowley, but he does so in order to fight Raphael and prevent the apocalypse from re-starting. In order to carry out his plan though, he is forced to lie to and manipulate the Winchesters while carrying out some pretty morally ambiguous schemes. He undoes some of the worst ones though rather than risk the Winchesters, but ultimately finishes the season on a Heel note, having absorbed millions of souls from Purgatory and declared himself the new God. He seemed to come back to himself within an episode or so of the seventh season and asked for forgiveness only to be taken over by Leviathans who then, a few episodes later, appeared to liquefy him. About halfway through the season, he turned up again with amnesia. He got his memory back and took the broken wall in Sam's mind onto himself, effectively bringing Sam back to normal, but landing himself with an incredibly messed up head. As of the end of Season 7, he seems to be on the Face side, having made a Heroic Sacrifice. As of the middle of Season 8, he's apparently back to Heel, being Brainwashed and Crazy for Naomi. In the episode "Goodbye, Stranger", he leaves both sides behind and goes off on his own. Expect this section to expand continually.
Crowley is Castiel's opposite; he desperately wants to be the Big Bad, but circumstances and greater threats keep forcing him into Enemy Mines with the heroes. When we first meet him in season 5, he helps the heroes fight Lucifer because he correctly believes that once humanity is destroyed, Lucifer will turn on the demons. Once Lucifer is dealt with, however, he declares himself the King of Hell and spends most of season 6 as an antagonist. But once season 7 rolls around the new threats of Castiel and the Leviathans force him to reluctantly aid the heroes again for a return to the status quo. But of course, as soon as that's dealt with, he immediately betrays them and goes back to being a bad guy for season 8. Season 8 ends with Crowley's humanity being partially restored and Knight of Hell Abbadon announcing her plans to usurp Crowley's throne, so it wouldn't be surprising to see him back on the side of good (or at least as close to the side of good as he ever gets) for season 9.
In Season 9, Gadreel's allegiance is all over the place. He starts out as a gardian in Heaven, then he lets Lucifer inside and is punished for his crime. After his unexpected release he tries to atone by helping Dean save Sam, only to be convinced by the conniving Metatron to join his new army. He joins the Winchesters again, but the vengeful Dean is having none of it. Gadreel eventually helps Castiel infiltrate Heaven but fails and commits suicide in a final act of atonement.
There's an odd version in season five when Dean realizes where his current path leads after he's sent into the future and meetshimself.
The moment at the end of season four after Sam has killed Lilith and Ruby revealed that Lilith was the final seal, not the one who was going to break the final seal, is Sam's moment when he realizes he's just an Unwitting Pawn who screwed up big timeand brought about the apocalypse. His face conveys complete devastation and he's barely even paying attention when he and Dean kill Ruby.
Hell: Home to the demons and place of torment for damned souls. Time appears to move more slowly there for imprisoned souls, thus making an eternity of torment seem even longer.
Hell Hound: The series has invisible hell hounds that work for demons. They can only be seen by the people they've come to kill.
Hell Invades Heaven: This seems to be Lucifer's PR to his demon mooks after they release him and start the Apocalypse. Meg cheerily taunts a captured Castiel that they're going to win against the angels and invade Heaven itself. In reality, Lucifer wants the demons to have no part in his plans and considers them worthy of annihilation.
Hell on Earth: Sam breaks the final seal by killing Lilith and Lucifer is unleashed from his imprisonment. Lucifer's intention is to do this, making Hell on Earth. Ironically the demons aren't to be a part of it, as the Archangel absolutely despises them and wants to wipe them out along with the humans, so he can preserve his Father's last flawless creation.
In "Abandon All Hope", Ellen and Jo (who was already dying from being slashed by a hellhound) lure the hellhounds into their hideout and blow up the building, allowing Dean and Sam to escape and try to kill Lucifer.
John exchanges his life and soul for Dean.
Deconstructed with Dean's Deal with the Devil to sell his soul for Sam's life, which is portrayed as more of a product of Dean's abandonment issues and lack of self-worth than heroism.
Sam with his whole in season five finale Swan Song: He throws himself (and more to the point, Satan, who's possessing him) into hell's solitary confinement in order to prevent the planet from being razed, with certain knowledge that Lucifer's going to spend eternity torturing him.
Shown by John in "Devil's Trap" when he is able to resist and trap the possessing Azazel for a moment, and by Dean in "The Magnificent Seven" when he resists Lust's charms. Averted in "Sex and Violence" when Dean and Sam are helpless against the siren's spell and need Bobby to bail them out.
Dean, who apparently resisted Alastair's offer to escape torture in Hell by torturing other souls. He refused the offer every day for thirty years. However, this pales in comparison to John Winchester, who refused the same offer for one hundred years, and then escaped Hell.
Displayed by a demon-possessed Bobby in "Sympathy for the Devil" when he breaks the demon's hold just before it can kill Dean, and instead, stabs himself with Ruby's "kill-all" knife.
Sam in season five finale Swan Song took control of his body while the devil was riding it just so he could throw himself and the devil into hell's solitary confinement.
Sam in season 6 finale. He manages to overcome his "inner demons" and drag himself to assist Dean and Bobby in the battle against Castiel and Crowley despite obviously suffering under the strain of his "hell memories".
Gordon Walker is the purest example, literally becoming worse than the monsters he hunts taking them out.
John was this way about everything related to Mary's death, hence the obsession with YED.
Dean whenever he's lost family. Such as when he encounters Gordon in season two after his father dies; when he so loses faith in his brother that he agrees to the angels' plan in season five even though it will destroy most of the world; and in season seven when he kills Amy Pond (not that one) because he can't trust a monster not to kill again, complete with a Beatrix Kiddo moment with the woman's son afterward.
Sam was this after Dean died in Mystery Spot and the season three finale. While he thinks killing Lilith is the only way to prevent the Apocalypse and feeding demon-blood-fueled powers also lets him save the hosts when exorcising demons, his obsession with killing Lilith leads him to break the final seal, releasing Lucifer from Hell.
Future Dean in "The End" (5x04). After losing his brother to the devil and failing to stop the apocalypse, he becomes heartless and unsympathetic, willing to sacrifice all of his loyal friends for a chance to kill Lucifer.
Hiding Behind Religion: Castiel eventually decides to go on a rampage against these sorts of people. Among other things, a homophobic reverend is killed in front of his flock, a corrupt right-wing senator is slaughtered along with her campaigners, and racists take such a sound beating that the Kuu Klux Klan is forced to disband.
Hollywood Healing: Throughout the series, though very noticable in "Shadow" when the Winchesters get their faces slashed up by a shadow demon but show up in the next episode completely scar-free.
Hollywood Nerd: Played straight by Felicia Day's character in "The Girl with the Dungeons and Dragons Tattoo." She is, well, Felicia Day. She's never really shown to be socially awkward (Adorkable situations aside), and not treated as such, and her devotion to her nerdy pursuits is certainly not in question. Just a regular geek that's treated in universe like a nerd.
Hollywood Psych: Averted. If it gives them a chance to increase the depression some more, then they're usually very good with psychology.
Holy Halo: In season 8 the Angels are confirmed to have them when a Nephilim says she can see them, but like their wings they are invisible when they're in their human hosts on Earth.
Holy Is Not Safe: Angels can possess people as well as demons, although they require consent, but anyone imagining angelic possession won't leave them worse for the wear is in for a grave disappointment. Those who're possessed are liable to end up like lobotomy victims.
Dean, in regards to Sam, in "Born Under A Bad Sign." But of course, this show being what it is, they do their best to try and break him because of it.
Sam, with several human enemies and a few monstrous ones. Not killing human Gordon leads to being hunted by him yet again, but not killing vampire Lenore turns out to be useful. Yet still horribly sad.
Hookers and Blow: Dean is flung a few years into the future to see the outcome of his choice of action. They lost. Future!Castiel is seen arranging orgies and doing drugs like there's no tomorrow. Because there might not be. He's also been turned mortal.
The Wendigo and Rugaru are former humans who transformed into man-eating creatures (although for different reasons.
The Crocotta, Wraiths, Rhakshasa and probably others are monsters who eat humans or part of them (like their soul).
Sam Winchester in season 4 becomes addicted to demon blood
Famine can push people's desires Up to Eleven, and he himself eat souls.
The implication in the last two episodes of season 4 that Lilith eatsbabies is suggested in season seven to be something demons equate with rank. Whether this is necessary or just overkill isn't specified.
The kitsune who show up eat human brain material. It's specifically stated to be mandatory, and Amy normally gets by with material scavenged from the mortuary but her son becomes ill without fresher brain matter. (Amy gets it for him, so we don't actually see a kitsune overwhelmed with hunger at any point)
Horsemen of the Apocalypse: War shows up in "Good God, Y'All!" driving a red Mustang. "Abandon All Hope" ends with Lucifer greeting the newly-summoned Death, though we don't see Death until "Two Minutes to Midnight," in which Death informs Dean that Lucifer didn't summon him so much as bind him to his will, which really irritates him. Famine appears as a withered old man in "My Bloody Valentine," and Pestilence shows up at the end of "Hammer of the Gods".
All the Horseman drive cars with their cooresponding colors and theme. War has a cherry red 1965 Mustang Fastback, Famine gets driven around in a black Cadillac Escalade, Pestilence rides a rustic green 72 AMC Hornet station wagon, while Death is seen having a pale white 1959 Cadillac.
The recurring Crossroads Demons may be in a different body every time, yet, somehow, they are always hot women. Invoked, since they're specifically using those hosts to make their deals more palatable to their male clients, which is sealed with a kiss.
Humanoid Abomination: A lot of creatures in the series hijack human bodies because their real forms are incorporeal, but the Angels are the only ones who qualify for this trope. Their celestial forms are decidedly of the Eldritchy variation, variously described as "multi-dimensional wavelengths of celestial intent" and the size of the Chrysler building. Whenever they appear in their true forms, all that is seen is a blinding light that engulfs the entire area, a booming deafening sound that are apparently their voices, everything in the vicinity getting destroyed due to their awesome presence, and are so much of a Brown Note that any humans nearby have their eyes burn out of their sockets and die. To manifest on Earth they use human vessels, which are purely intended as A Form You Are Comfortable With.
Human Sacrifice: The Winchesters encounter numerous pagan gods imported to America that survive on human sacrifice. One god grants the community it lives in the traditional benefits of its presence and appeasement, including bountiful harvests and mild weather. On some occasions the Winchesters arive to thwart the sacrifice, on some occasions they are the sacrifice. Every other god is portrayed as man-eaters, implications abound.
Humans Are Flawed: This is what Gabriel actually believes. His speech to Lucifer in "Hammer of the Gods" contains exactly that trope.
Hypocrite: Keeping track of how often the Winchesters rely on supernatural solutions to supernatural problems, or cut dubious deals with everyone from demons to Death himself, is an overwhelming task. Often, a large number of their problems arise from prior recourse to such things.
Sam accepting mentoring from Ruby, drinking demon blood and using his otherwise latent psychic powers leads to disaster.
Dean selling his soul to save Sam.
Anytime anyone cuts a deal with Crowley or even just accepts his help.
Subverted twice for Sam. In season two episode "Born Under A Bad Sign" Sam pleads with Dean (who obviously can't) to kill him after he kills another hunter while possessed. At the end of season four in "When the Levee Breaks", while suffering withdrawal from demon blood, Sam tells Bobby to shoot him if he wants to help.
Played straight in "Heart." Sam's one night stand was a werewolf, but they cured her... except not. There's no cure and she'd already killed a few people, so she asks Sam to shoot her instead. Ouch.
Iconic Outfit: Castiel. The holy tax accountant suit, loosened tie and signature trench coat combo—work it, Cas. In the seventh season premiere, he went to a church and replaced the standard Christian stained-glass painting of God/Jesus with himself....in that same outfit. Man, Castiel must love that suit and jacket.
I Have Many Names: The Reapers, apparently. When Dean meets a particular Reaper again in "Death Takes A Holiday" who tried to guide him to the afterlife in a previous episode, she restores his memory with a kiss. When he calls her "Tessa", the alias she used while disguised as a human, she simply replies "Yes, that is one of my names".
Sam ran away to college, where his girlfriend was killed, and spent the first season wanting to go back after they defeated the Big Bad. Then he found out he had demonic powers and after getting a taste of The Dark Side, decided he was too much of a freak to ever have a normal life.
Dean has wanted out of the life since Dad told him he might have to kill his brother. Losing his brother, first to death and then to demon blood-addiction, made Dean want to settle down to a life with a normal family by season six.
Runs in the family. Their hunter mother desperately wanted to get out, raise a family and live a normal life.
Subverted humorously on one occasion where Sam is forced to switch bodies with a teenager via witchcraft. Sam lies to the kid that he'd give anything for his life, then tells Dean, "that kid's life sucked" (which was basically true).
"I Know You're in There Somewhere" Fight: Despite Sam's attempts, this completely fails on Dean in "Sex and Violence," and on Jack in "Metamorphosis." Also fails on Sam despite Dean's attempts in "Asylum." Other than Lenore in "Bloodlust," the only two to manage it are John Winchester and Bobby Singer. Also seen in "Swan Song", though it's more of a "I Know You're In There Somewhere" beating, since Dean's not actually fighting...
I Let Gwen Stacy Die: Sam's girlfriend died the same way Sam and Dean's mother did. This gives Sam the incentive to leave his old life behind and hunt demons with Dean. Sam feels responsible for her death because he wasn't there to save her and he saw her die in prescient visions but didn't believe them.
Imaginary Enemy: In the seventh season, Sam begins hallucinating that Lucifer (the Big Bad of season five) is tormenting him as a result of having his soul mangled in Hell. Even though this Lucifer is a hallucination, and Sam knows he's a hallucination, he still manages to cause quite a bit of trouble, including invoking Schrödinger's Butterfly and nearly tricking Sam into shooting his brother Dean. The hallucinations get worse as the season progresses, until finally Sam has a mental breakdown and can't even manage basic functions like eating and sleeping. Castiel saves Sam by transferring the hallucination to his own mind. Being an angel, he eventually recovers.
In "My Bloody Valentine," a man and woman on a date really, really want each other, so much so they go from kissing to devouring each other alive. The woman's roommate says that when she found them, the man, while dying, was "still chewing." It turns out that they are driven to this by the presence of Famine, one of the Four Horsemen of the Apocalypse.
Wendigos were humans who became monsters by succumbing to cannibalism.
Subverted in season 3's "Time Is On My Side" with an immortal doctor who needs to replace his organs when they "wear out"; Sam steals his notebook, complete with the formula for how to become immortal. Turns out it's not some dark magic ritual that involves drinking blood from a baby's skull, its just science — though "weirdscience". The brothers eventually bury the notebook with the doctor, not wanting to have to prey on others to survive. It seems like they didn't stop to consider the positive implications of that kind of immortality paired with organ cloning technology...
And subverted again in the season 5 episode "The Curious Case Of Dean Winchester", where the leads come across a witch who lengthens his life by playing Texas Hold'em with humans. At least 25 years of life is the buy-in: winning means you can regress to your younger self or not age for that amount of time, while losing means you age rapidly or die. There are no tricks involved, as the only ones who play the witch are those who search him out knowing full well what the game entails. Interestingly, the witch never cheats (he's been playing and winning so long, he doesn't feel the need to), tries to dissuade potential players whom he believes don't have a real shot at winning, and on one case, he folds a hand he's certain he'll win and voluntarily ends the game, just to give an aging opponent enough extra years of life for him to see his granddaughter's Bat Mitzvah. He's a pretty nice guy.
Impersonating an Officer: The brothers impersonate police and FBI agents a lot to get close to witnesses, as do several other hunters. Bobby backstops the boys' aliases if someone wants to call their superior. One episode shows Bobby has a whole wall of phones labeled with each alias, though in the same episode the trope fails because it turns out the sheriff they're talking to knows Bobby. This backfires when they're investigating a LARP event - one of the LARPers identifies their FBI badges as fake because he used similar ones in the past, congratulates them on the quality, then chews them out for being dressed for the wrong setting.
When Sam comes Back from the Dead in season six, he ties Dean up so that he won't attack him, then cuts himself with a silver knife and swigs a mouthful of salty holy water to prove he's really himself. Dean had the same set of tests run on him when he got back from Hell.
In another episode, a parasite has infected one of the characters, but they can't be sure who. They had earlier figured out that electricity was so effective on the parasite that it would be forced to leave the host, so the characters had to take turns shocking themselves to prove they didn't have it.
In Mysterious Ways: God's presence is 0% for the first three seasons. Then in season 4, He sends an angel to revive Dean from Hell and starts being a lot more proactive. When Dean questions Castiel about it, Castiel begins to state this trope, but Dean cuts him off and warns him, "If you say 'In Mysterious Ways,' so help me I will kick your ass." A later episode shows that God's ways are so mysterious, even Castiel doesn't know what's going on.
The archangels, and Lucifer, all seem very certain their father is real, but that he is either dead or just gone forever. As one might imagine this distresses them. Castiel wants to find him and ask what's up.
They found out from an angel named Joshua that God is on Earth and aware of Apocalypse, but simply doesn't care. Cue to severe despair for Dean and tremendous lost of faith and start of severe alchoholic problems for Castiel in following episodes.
Later it is implied that Chuck, the prophet who began writing Dean and Sam's adventures for profit, might have been God the whole time and was slightly guiding them. Of course, considering some hints from Gabriel, Lucifer and others and the way all angels and humans are, it still doesn't excuse him of being one hell of a lousy father, considering Gabriel decided to ditch them and turn into the Trickster, Lucifer... well, you know the rest. In retrospect, this means that when Chuck was apologizing for making them live bad writing, he was apologizing for their entire lives.
In a later episode (Reading is fundamental) Castiel outright invokes this trope by reacting to Dean's question on what kind of sense some angelic plan makes with "That's god and his shiny red apples."
Incoming Ham: Gabriel when he steps into the conference of gods. "Can't we ALL just GET ALONG?"
Done a few times when it comes to describing people as intelligent. Besides the odd character like Sam and Ash, who demonstrate that they are especially knowledgeable in certain fields, often the writers will just throw in a toss away line that explains that the character in question reads/owns a lot of complicated books so they must be smart, despite often making horribly poor decisions and never doing or saying anything that might demonstrate said intelligence.
Sometimes their "great" hunting skills, especially in Season 1. John Winchester sticks out: touted as pretty much the best hunter ever, yet literally all of his appearances see him screwing up and needing to be rescued by Sam and Dean.
The Jefferson Starships are so named because they're "horrible and hard to kill." This is after the group slew an entire police station of them with relatively little effort.
In a highly unexpected Subverted Trope - notable for how rarely a show successfully pulls it off, the season 2 episode "Crossroad Blues" features a man who sells his soul in order to become a great artist. They do actually show a number of his artworks, all of which are interesting and emotive. How great they actually are still remains a matter of opinion, of course, and the writers acknowledge this by having the character create artworks that he pours his heart into, but never actually manages to sell.
Played straight with Gordon Walker, a hunter who specializes in vampires. He's supposed to be among the best at tracking and killing them, but two of the three vampires we see him fight manage to get the upper hand. The first time he's bailed out by Sam and Dean, the second he's not so lucky.
The Leviathans, main enemies of season 7, are supposed to be even more powerful than angels, and demonstrated when Edgar easily dispatches two angel mooks. The problem is there is little outside this scene to indicate this is actually the case. Angels are super strong, able to teleport, Nigh Invulnerable, capable of healing major injuries and resurrecting the dead, can kill most monsters and demons just by touching them, and can even Time Travel and alter reality. In fact, they're so powerful that in three seasons Sam and Dean only ever managed to outright kill one angel -And even then, only because Dean took him by surprise. Leviathans are also Nigh Invulnerable and can shapeshift, but have little else going for them, and have actually had trouble fighting demons, witches, ghosts, and even normal humans, all of which were previously established as being much weaker than angels. So rather than actually making the Leviathans seem frightening, the scene just comes off as a desperate attempt to establish the leviathans as a credible threat by invoking The Worf Effect.
David Lassiter (shapeshifter) / Violet Duval (werewolf).
In the Blood: Dean, John, and Mary all make deals. Sam's powers are the result of one such deal letting a demon feed him its blood, and he actually takes a demon as a mentor and drinks her blood to fuel his powers.
Destiny also grabbed the Winchesters by the veins in that they are apparently descended on both sides from a line of archangel vessels, and were born to house Lucifer and Michael for their final apocalyptic battle on earth.
Lampshaded in "It's a Terrible Life" where Zachariah's lesson was meant to teach Dean;
Zachariah: The path you're on is truly in your blood. You're a Hunter. Not because your dad made you, not because God called you back from hell, but because it is what you are. And you love it, you'll find your way back to it in the dark every single time and you're miserable without it.
The Man of Letters Henry Winchester is dismayed at first to learn that his son and his grandsons became mere hunters, but later admits that they're still his descendants, and if circumstances were different, would have made brilliant Men of Letters themselves.
Insistent Terminology: Sam asks that Dean not call him "Sammy" in the first episode, saying that it's a kid's name. It doesn't stick.
The Insomniac: Sam starts staying up all night in the first season when he's having nightmares about Jessica. In a much creepier example, he also stops sleeping entirely in season six, when he's lost his soul. And for several days in season seven, to the point where he nearly dies, after the hallucination of Lucifer left over from his time in hell becomes unbearable.
Instant Expert: The psychics in the show are able to develop their powers quickly if they give in to the demon's will; regular practice doesn't have as sudden and extreme results.
Internal Reveal: The fact that Sam was drinking demonic blood to power his psychic exorcism powers was revealed to the audience in 4x16, "On the Head of a Pin." Dean didn't find out until 4x20, "The Rapture." He wasn't happy.
Interplay of Sex and Violence: Most female demons, especially Ruby, Meg, and Dental Hygienist!Lilith, love macking on the boys while smacking them around.
Invasion of the Baby Snatchers: "Children Shouldn't Play With Dead Things" had this with a rather frightening twist; the children were replaced by changelings, exact replicas of the real thing, but they sucked blood from their mothers and killed their fathers. The real children were kept in cages.
Invisibility: "Wishful Thinking" had an invisible kid (among a few other things) due to a real (evil) wishing well. The kid wished for it purely so he could peep in the ladies' locker room. Late in the episode, he gets hit by a car (he lives), but it's unclear whether this is due to the kid's bad luck or the well causing the bad luck to happen.
Invisible Jerkass: In the "Wishing Well" episode, a boy wishes to become invisible so he can spy on women in the shower. It fails, due to the kid's complete lack of reflex and agility.
"Everybody Loves a Clown" and "The Kids Are Alright." LIES!
"Jump the Shark" seems like this at first. That it was the least viewed episode of the season in America isn't exactly a big surprise.
It's All About Me: Done in the season premiere episode I Think I'm Gonna Like It Here, Dean goes to so much absurd extremes to try to save Sam when Sam wants to die, and because of Dean's issues he can't even fathom going on without him.
It's All My Fault: Done four times to Dean: in "Faith" when he's dying, Sam takes him to a faith healer and he's healed, except someone else died for him; the entirety of Season 2 over his dad dying to save him; when Sam dies in "All Hell Breaks Loose"; and starting the Apocalypse. Of course, Sam tries to claim the same for his role in breaking the last seal, and though neither were entirely at fault, it still doesn't stop them from blaming themselves. He blames himself for Jo and Ellen's deaths as well. Face it - Dean's just got issues with this. There's a bit early in season 7 where Dean, only half-joking, says, "Unemployment? That's on me."
Dean: There's always something eating at me. That's who I am. Something happens, I feel responsible, all right? The Lindbergh baby—that's on me. Unemployment—my bad.
It reaches a tear-filled culmination in the Season 8 finale as well, with Sam admitting that his foremost confession to purify his blood for the use in the demon-curing exorcism was the admittance of how he failed Dean. It only spirals downwards from there.
Jerk Ass: John is the hated/despised/loathed but pitied kind, Dean is the "I'm about to break down any second" kind, and Sammy is the "You have no idea how I feel" kind.
Jerkass Gods: All of the pagan gods on the show including the "nicer" ones like Balder are human-eathing monsters. The sole exception is Prometheus who is a type of "proto-god." God himself is supposedly good, but comes across more as a deadbeat father whose abandonment of heaven have caused all the major problems in the show from season 5 onward and has done nothing about any of those problems or the general mess Earth has been.
Season 2, "Bloodlust". The Winchester brothers met rogue vampire hunter Gordon Walker while looking for a nest of vampires. Gordon seems like a decent enough chap and a worthy ally, and Dean likes his "kill all the monsters and enjoy the hunt" philosophy. Dean and Sam end up fighting when Sam reveals that other hunters say Gordon is bad news. Before this can go any further, Gordon takes a swandive off the slope when the local vampires turn out to actually be peaceful, having sworn off killing humans, yet he still attempts to slaughter them. Then he tries to feed Sam to the head vampire to prove she's still a monster, and attacks Dean when they try to protect her. Bad move.
This is Castiel's entire character arc during Season 6. Desperate to defeat Raphael in the civil war in Heaven, Castiel begins performing many morally questionable acts, not the least of which is allying with Crowley, and rapidly skipping several shades of grey. This ultimately culminates in the season finale, where he jumps right into Villain Protagonist territory when he absorbs all the soul energy of Purgatory and declares himself the new God.
Whilst on a smaller scale, Castiel's ascension to God and later 'death' causes Dean to take a much harsher stance on supernatural beings throughout Season 7, most apparent in 'The Girl Next Door'.
Just Between You and Me: None of the demons seem to be able to resist the temptation (except for the BigBads). The rest of the monsters are strangely immune.
The witch in "The Curious Case of Dean Winchester". He's still alive at the end of the episode, and there's no sign that he's going to stop what he's doing anytime soon. But there really isn't a reason he should, he basically says all the rules for playing his game, dissuades you from continuing playing it if it will kill you, and doesn't rip you off if you come out ahead. He actually is happy when a player gains enough time to witness certain events, and he doesn't kill Sam and Dean when had so many chances.
Even Don and Maggie Stark from Season 7 episode, "Shut up Dr.Phil" qualify too. This case is the oddest. It's set a few episodes after Dean kills Amy, which he did because she might kill again, even though she only did it to save her son, and only on criminals. Not saintly behavoir but still understandable. Maggie Stark kills 3 upstanding citizens who protected her husband's affair, Disproportionate Retribution. And Don kills one of Maggie's friends just to get back at her a bit. Maggie tries to kill Sam and Dean as well, but Don saves them from that, and a Leviathan. This apparently excuses them from the fact that they killed four people, are implied to have had squabbles thorought the centuries so other murders are likely. Despite the fact that Sam is still mad at Dean, and Dean killed Amy to be safer than sorry, this issue is never brought up.
In Don and Maggie's case though, the brothers TRIED to kill them - they shrugged it off and only neglected to kill the Winchesters on the spot because they considered arguing about the affair more important than a pair of hunters in their house. After Don handed them a Leviathan on a silver platter, without which they would never have found their weakness, AND saved them from death at Maggie's hands again they probably figured it was best to live and let live.
A straighter example is the episode "Tall Tales". The Trickster has killed and abused multiple people in a set of dangerous pranks, and gleefully indulges in the perks his powers provide him. Sam and Dean seem to have killed him at the end of the episode with Bobby's help, but after they leave it's revealed to be a trick that the Trickster played on them, and they only killed a projection of him.
Keeping Secrets Sucks: the few times Sam keeps a secret from Dean that isn't toopersonal. And every single time Dean has to keep a secret from his brother (granted, that's mostly because he only keeps secrets about his brother's fate or things he's done that Sam wouldn't like).
Bobby became a hunter after he killed his wife when she was possessed by a demon. Then he kills her again when Death brings her back to life but learns that she's turning into a flesh-eating zombie. Naturally it pains him a great deal.
Bobby: She was the love of my life. How many times do I have to kill her?
This is the background of recurring antagonist Blood Knight Gordon Walker, whose sister was turned into a vampire.
In the season one finale John Winchester ordered Sam to shoot him with the Colt to take the demon out as well. (He didn't.) And a few episodes later John's final direction to Dean was that he 'had to save Sam,' or he 'might have to kill him.'
Sam's mid-Season Two insistence that Dean promise to do just that if Sam goes darkside. Dean promised. He was lying.
Sam's first girlfriend after his episode-one bereavement turns out to be a werewolf who asks him to kill her. Or there's that time Sam nearly strangled Dean to death, or that time Sam shot Dean, or that time Sam was possessed and shot Dean, and possessed and killed him in the Bad Future.
Downplayed in Season Six, with soulless Robo-Sam determined to prevent Dean from restoring his soul. Rogue angel Balthazar informs him that to get his soul to reject reunion with his body he needs to pollute it with a crime such as patricide. Robo-Sam can't feel love, but apparently Sam's regard for Bobby as a surrogate father is enough for murdering him to be 'good enough.'
Plenty of lesser instances, particularly where family members or Love Interests of both recurring and incidental cast turn out to be or turn into monsters.
Kiss Me, I'm Virtual: In "Dark Side of the Moon", Zachariah reveals that he uses a simulation of Sam and Dean's mother as a sex toy, much to their disgust. He even calls her a MILF.
Knight Errant: Sam and Dean, but primarily Sam. While they may have other goals during the series - finding their father in Season One, trying to negate Dean's contract in Season Three - they always stop by in whatever wayward towns are being haunted even if they don't have personal reasons to, and deal with the supernatural threats there.
Knight Templar: Gordon Walker of Supernatural is a hunter who tries to kill Sam Winchester and other psychic kids because he firmly believes that they'll turn against humanity and that Sam is the Anti Christ. He considers his position unassailable enough that he won't let morality stand in the way of stopping Sam.
Nearly all the angels qualify, considering they believe that they're following the will of God. And most don't want to let free will get in the way of that.
And since the end of season six, also Castiel—well, until he becamemuchworse...
Lucifer himself viewed humans as murderous apes who ruined planet Earth, which he referred to as God's last perfect masterpiece. His Humans Are Bastards belief as well as his self-centered, self-righteous personality caused him to rebel against God.
Kraken and Leviathan: The Leviathans are not giant sea creatures, but rather are perfectly capable of living on land and while they are seldom seen in their true form, there's no sign that this true form is any bigger than the human disguises they use. But there are good mythological reasons for calling them by the name "Leviathan": Their backstory is related to biblical mythology; they are Eldritch Abominations that are all about having a predatory appetite; and when their true form is shown, the view isn't very clear, but it definitely has More Teeth than the Osmond Family.
Leaning on the Fourth Wall: This is approaching the point of being a running gag during the last few seasons. First, the Winchesters discover that they have been written about in a popular book series (complete with fan-girls and fan-boys), then they meet the author of said books, who apologizes for the poor writing in certain panned episodes. In a later episode, they even went to a fan convention all about the Supernatural series. And this is saying nothing of Dean's "they do know we're brothers, right?" reaction when he finds out about Wincest...
Also in Supernatural, Castiel is named after an angel who in lore helps people who travel a lot and is an angel of Thursday. The Winchester boys travel a lot, and guess what day the show aired at the time?
There was also Crowley's remark to Castiel in a Season 6 episode: "Castiel. Haven't seen you all season." The fact that it was a bald-faced lie aside, it was an odd way to phrase the greeting, unless it was a passing bit of fourth-wall leaning.
Crowley does this again with Castiel when he mentions that Cas is the angel of Thursday and today wasn't his day. During that season, Supernatural switched to Friday nights.
"It's about time we had a nice black and white case." was spoken at the start of the episode that was shown in black and white.
In "There Will Be Blood," the Alpha says, "See you next season." as Sam and Dean are leaving.
What about the meta episode in season six? Misha playing 'himself', Jared's wife being 'Ruby'?
In the Season 2 episode "Hollywood Babylon," Sam remarks that the (strangely overcast) weather in L.A. is "practically Canadian." Supernatural is of course shot in Vancouver, Canada.
The Legions of Hell: Whole bunch of demons get out of hell in "All Hell Breaks Loose, Part II." In "The Magnificent Seven," Envy (yes, that Envy) says "We are legion." And there's a horde of attacking demons in "Jus in Bello."
"Dean's Family Dedication Theme." Upsetting when it's being played at moments where his family love gets a little too obsessive, heartbreaking when it's being played at angsty moments (Sam and John's deaths, for example) and fucking unbelievably painful when Sam is crying over Dean's dead body in "No Rest For The Wicked," where it's being played as a funeral dirge.
Death is given "Oh Death" by Jen Titus, which plays in his introductory scene.
Lesser of Two Evils: Subverted. Lucifer the archangel is released in season 5 and starts the Apocalypse, and the Winchesters are stuck in a battle between Hell and Heaven. The demonic armies want to destroy the Earth and take over Heaven, although Lucifer plans on killing them too, while the angelic bureaucracy is barely better, being a corrupt military theocracy who want to bring about Paradise and find the slaughter of half of humanity in the ensuing fight between Lucifer and Michael acceptable losses. The Winchesters are too powerless to kill either of them, and after being stuck between two bad options for an entire season Dean almost gives in to Heaven's demands, but the team pulls him back and they continue looking for more options.
Let's Split Up, Gang: Happens a few times, but most notably in "Skin", when the brothers are hunting a shapeshifter. See where this is going?
Liberty Over Prosperity: This is Sam and Dean's motive for rejecting the angels' plan to destroy the earth and rebuild it as a heaven.
Dean: You can take your peace...and shove it up your lily-white ass. Cause I'll take the pain and the guilt, I'll even take Sam as is. It's a lot better than being some Stepford bitch in paradise
Castiel:(a season later) You got what you asked for, Dean. No paradise, no hell, just more of the same. I mean it, Dean. What would you rather have? Peace...or freedom?
In "Something Wicked", an immortal creature called a shtriga drains the life force from people, mostly children.
In "The Curious Case Of Dean Winchester", a 900-year-old Irish witch uses an enchanted card game to "win years" from his opponents, and used them to extend his own life and that of his wife, who had become tired of living forever and wanted to die.
Light Is Not Good: All but two of the angels seen so far are manipulative dicks who despise humanity just as much as the demons do. One of them tries to stop Sam and Dean from being born, in an attempt to stop the Apocalypse. To be fair though, that's implied to be a result of Brainwashed and Crazy and Being Tortured Makes You Evil. The other eventually goes nuts, and declares himself the new God.
Sam seems to have gotten over the get over Dean's death lesson pretty quickly. Even Dean calls him on it. Of course, since the lesson never stuck in the first hundred times the trickster/Gabriel tried it, he didn't exactly get over it.
The Lost Lenore: Sam and Dean's mother for them and their father, Jess for Sam, Bobby's wife.
Lotus-Eater Machine: Heaven works this way, with each individual soul (or pair of soulmates) occupying a personalized paradise meant specifically for them. Unfortunately, each soul (unless they have a soulmate) is actually alone in their Happy Place and any loved ones they interact with are just fantasies. These other people may not even be in Heaven. They could still be on Earth, in Hell, Purgatory, etc. However, at least one clever individual, Ash, figured out how to move between different people's personal paradises.
Loveable Sex Maniac: Dean, natch. Future!Castiel may also qualify, considering his casual attitude towards group sex.
Love Goddess: Angels of love are called "Cupids", who manifest as nude men rather than diapered babies.
Season 8 shows us that they can masquerade as inconspicuously dressed men, or even women, if necessary.
Love Interest Traitor: Sam's love interest Ruby turns out to have been manipulating Sam into freeing Lucifer.
In season seven, Becky uses a literal love potion on Sam. It goes well enough for her, with no one else affected, the potion not being too strong, etc. The only problem is that she doesn't have enough of it, so she has to resort to restraining Sam to keep him from escaping. She decides to let him go when she learns that it would cost her soul to keep him for a few decades.
In season 8, there's a man who made a demon deal to make a woman fall in love with him, with the effect dissipitating after the demons collect his soul.
Lowered Monster Difficulty: The series has moments like this in some episodes. The wendigo in the same-titled episode is shown to be a lightning fast, shadowy death machine and an expert hunter. Yet when the main characters confront it in its lair it just lumbers along casually despite the fact it knows they have weapons that can hurt it. It's not really surprising when it dies in one shot.
Lucky Rabbit's Foot: One of the episodes centers on a cursed rabbit's foot. If you touch it, as long as you had it in your possession, you have phenomenally good luck. As soon as you lost it, your luck would turn and soon you would die through sheer bad luck.
La Résistance: Future!Dean in "The End" is the "fearless leader" of some of the few remaining humans.