In one episode Dexter and Mandark fail to stop an asteroid from destroying the world due their refusal to work together. The two fail to notice this, still bickering inside their mechs in outer space. Thankfully, that doesn't mean much here.
The ending of "The Way of Dee-Dee" is pretty sad as well, with Dee-Dee's attempt to get Dexter to enjoy himself end with Dexter wrecking his own lab, and Dee-Dee apologizing to him for trying to change him, and running to her room in tears. The last scene is Dexter noticing the destruction he caused and quietly working to repair his lab. It's a genuine Tear Jerker in the show, one of only a few.
"The Big Cheese" ends with Dexter, possibly permanently, only able to say "Omlette du fromage," locked out of his lab, which is then blown up completely while Dee-Dee mocks him.
Oh, "Dexter's laboratory" had plenty of these! And there's only one episode ("Unfortunate cookie"), which ends with Dexter being better off than Dee-Dee.
The first two episodes where Mother Simpson comes back have melancholy endings. In the first, Homer sits for hours on his car after Mona is forced to go away again. In the second, she's alive but he doesn't know it. Even when he tells himself she's alive (after finding a 'message' that says 'I'm OK'), none of them show any signs of believing in it and the real message is a sweet down-to-earth one that they don't find. The third of these episodes has Mona Killed Off for Real, but it nonetheless ends on a more upbeat note.
Subverted in the episode "One Fish, Two Fish, Blowfish, Blue Fish", when it appears Homer has died in an armchair in the living room. In the end, Marge discovers Homer is still alive and he promises to live life to the fullest. The episode ends on a darkly comical downer ending as it shows Homer wasting his life eating pork rinds and watching TV, as usual.
The episode with Herb. Homer designs a car which nobody likes, yet it cost a fortune to make, and ends up putting Herb out of business. True, Herb should have paid more attention to the design process but still, it's pretty unfair...
This is why they made an originally-unplanned sequel episode, where Herb gets rich again and forgives his brother in the end (and Homer gets a nice new chair).
W.I.T.C.H. is more or less composed of nothing but downer endings, except for the season finales. The villain always tends to be one step ahead of the heroes and with each step closer to achieving their plans, all the heroes tend to get is motivation to do better next time... and they're lucky to even achieve that! The heroes are on the losing side of the war for just about every episode.
"Zuko Alone". Zuko offers to help out a small farm family by rebuilding their barn and protecting them from corrupt, dishonorable soldiers. He teaches the little boy to wield a sword and never give up without a fight. Meanwhile, Zuko remembers how back at home the only person who cared for him was Ursa. It seems almost as if Zuko will find some acceptance in his new life as a refugee. But when his fight with the soldiers reveals who he is, he gets run out of town by everyone for being the Fire Nation prince. Poor Zuko.
In "The Library", the Gaang may have found out crucial info about the Fire Nation, but this is little consolation for the fact that they are in the middle of the desert with no supplies, no transportation, and no way to find the kidnapped Appa.
"City of Walls and Secrets" also qualifies as this with Jet being arrested and brainwashed, Joo-Dee being replaced and the revelation of Ba Sing Se really being a dystopic and corrupt city where the Earth King is merely a puppet.
"Appa's Lost Days" has Appa endures all kinds of hardship, survives and makes it all the way to Ba Sing Se where Aang is, and just as the audience is gearing up for the happy ending... he's captured again and dragged down into the earth, leaving only a single footprint to show he was ever there.
Season Two finale "The Crossroads of Destiny" ends with The Hero being struck down during his Transformation Sequence, leaving him horribly wounded and believed dead; the heroes barely escape as the Earth Kingdom falls to the Fire Nation, which now rules the world almost uncontested; Prince Zuko has regained his place in the royal family as he tried to all along but at the cost of betraying his beloved uncle, and is left wondering if it was worth it.
"The Puppet Master", which ended with Hama succeeds in forcing Katara to use the technique she swore she'd never use.
"The Day of Black Sun Part 2: The Eclipse", where most of the invasion force is captured, and Aang must retreat with only a few allies. The only thing that came out of it was Zuko's Heel-Face Turn, but to them it seemed like a full Shaggy Dog Story.
The play of their adventures in "The Ember Island Players" ended in Aang's death and the Firelord's victory. Justified because it was shown in the Fire Nation, where that was the ending everyone pretty much wanted - and the only one the government approved, most likely. The government declared him a god the very next episode.
"And The Winner is...." Amon. Full scale terrorist attack leads to plenty of innocent civilians electrocuted or de-bent, with the surrounding harbour bombed, judging from the fires. None of the Equalists are captured. The best you can say is "at least Korra wasn't killed".
"When Extremes Meet". Republic City has undergone martial law, resulting in the imprisonment of hundreds of innocents, including Mako, Bolin and Asami. Korra goes to confront Tarrlok for using such horrible laws, nearly kills him, but then is blood-bent despite it not being a full moon, kidnapped and taken out of the city.
"Turning the Tides". Republic City is overtaken by the Equalists despite the efforts of Korra. Tenzin and his family are driven from their home after his wife gives birth. Lin Bei Fong has her bending taken away by Amon, though she gets it back in "Endgame".
Batman: The Animated Series had a couple of these. Such as at the end of the episode Mudslide, Matt "Clayface" Hagen's structural integrity is slowly slipping away and his girlfriend and scientist Stella has almost completed a procedure that will allow him to stay in his human state whenever he wishes... until Batman appears and turns off the machine in a rather cold, unheroic moment. Admittedly Hagen had to hurt several people and steal the technology and Batman originally offered to help Hagen himself, as well as claiming "the lab boys will take it from here", from which we can assume they would continue and finish the procedure. The two fight it out of the laboratory and Clayface is doused in rain, further loosening his integrity until the pair are hanging from a cliff. Batman loses his grip of Hagen and he falls into the water before dissolving completely (although later episodes reveal he was, of course, Not Quite Dead). The episode ends on a wide shot of the cliff, Batman climbing up and helping Stella who is now in tears. The tragedy of it all is somewhat dampened by the fact that this is a Shout-Out episode: Dr. STEELLLAAAAAA!!! hid her Frankenstein's lab in the Bates Motel, while Clayface himself resembles an Oscar statue.
In the sequel to that episode, the new Robin meets and becomes smitten with a cute girl who turns out to be an "extension" of the newly re-formed Clayface that accidentally developed a mind of her own. At the end of the episode she's forced to re-merge with her "father", and after Robin goes berserk on him demanding that he bring her back, Clayface can only inform him that "she" is simply gone. Later when the police are listing what to charge Clayface with, Robin bitterly says "Murder."
Batman even solemnly tells Robin at the end, "Sometimes, there are no happy endings."
The MovieBatman: Mask of the Phantasm ends on quite a low note as well. After it is revealed that Andrea Beaumont is actually the Phantasm and she attempts to murder the Joker (as he was originally the hitman who killed her father), the theme park they are in is blown up and both Andrea and the Joker vanish in a cloud of smoke. Batman is left tending his wounds in the Batcave until he finds Andrea's locket, which she had left for him in the cave. The second-last shot of the movie is of Andrea standing on a cruise liner, alone. At the same time, Bruce Wayne accepts that he will always be alone and never have a normal life, accepting that he will always be Batman.
Come to think of it, EVERY episode of Batman: The Animated Series ends on a sad note in the earlier seasons, and quite a few in later ones. Some prime examples include "Tyger Tyger", "Baby Doll" (and its sequel episode, "Love Is A Croc"), and the series' final episode, "Judgement Day".
The episode "His Silicon Soul", which was a follow-up to a previous episode "Heart of Steel". A sentient computer called H.A.R.D.A.C. created robots to act as replicants to better help his creator's lab (by money i.e. robbery, etc.) before eventually taking over the city and then the world. When Batman shows up, a replicant of Batman is made in secret, but was hidden before it could be activated. Months later, it is activated by chance and unlike its predecessors was sentient in that it thought it was Bruce/Batman, but couldn't deal when he found out he was a robot. During the fight, the real Batman looks like he died (for a while) and the robot is so utterly horrified by this (remember it is based on Batman), it then goes and kills itself.
"Heart of Ice", which is considered to be the series' best episode. It won an Emmy for Outstanding Writing in an Animated Program AND made people feel sorry for Mr. Freeze!
Mr. Freeze: I have failed you. I wish there was another way I could say it. I cannot... I can only beg your forgiveness, and hope that you can hear me somehow... someplace... where a warm hand waits for mine...
Batman Beyond in general could be considered depressing when looking at Bruce Wayne's character. Rebirth was the first blow, where it appears that he ultimately loses in his personal battle against crime. Alfred's dead. Most of his sidekicks had left him on bad terms. Not even his Rogues Gallery is around. He just lives alone with a dog and a bunch of old memories.
Any Batman: The Animated Series episode involving Mr. Freeze is going to be tragic, but his apparent ending in Batman Beyond involves him finally gaining a human body and a girlfriend, both of which betray him in the end. He takes out a high-tech exosuit, is foiled by Batman, joins forces with Batman when Big Bad Derek Powers/Blight goes berserk, and sacrifices himself to save the new Batman. His last words are uttered in a completely heart wrenching, fatalistic manner, to boot:
Batman (Terry): You've got to get out of here Freeze! The whole place is coming down!
Freeze: Believe me... you're the only one who cares.
Other ignominious ends: Bane is permanently hooked up to the Venom drug just to keep his body functioning; original Batman and Batgirl had an affair that ended badly; the Movie with the aforementioned new Robin, the Joker, and the Kill Sat; the karate teacher's apprentice from BTAS is killed by snake-worshipping cultists.
The Batman Beyond episode "Heroes" also ended on a low note. The TerrificTrio are betrayed by the law enforcement forces, discover that there is no cure for their powers (and their conditions are actually getting worse), and that their co-worker (who more than likely may be Doctor Doom's analogue) knew all along what would happen and that he set the whole thing up to get the Ben Grimm/Johnny Storm analogue out of the way in order to have the Sue Storm analogue all to himself. All 3 of the trio members are implied to die horrible deaths and only the co-worker is confirmed to be left alive, with great remorse on his part. This is shown in the exchange between Terry and the co-worker:
Co-worker: No, you don't understand, I was their friend...
This was averted in the Batman Beyond episode "Eggbaby." A series that was originally dark to begin with, they specifically wrote a more lighthearted episode around the common theme of the parenthood high school project so that they could submit it for an Emmy. They knew this was the only way they had a chance since animation is for kids.
Batman: Under the Red Hood ends on an almost nihilistic note. Batman has been betrayed by Jason Todd, the Robin he believed dead, and had it rubbed in his face that his war on crime is unwinnable, that the Joker will keep escaping his cardboard prison to kill and maim until the day he dies, and that untouchable crime lords will continually hold Gotham in their grip. Any promise of a brighter tomorrow will be destroyed by the scourge of time.
Tiny Toon Adventures has probably one of the most infamous examples, especially towards Fifi LaFume fans. In the short "Out of Odor", Elmyra has her mind set on having Fifi as her pet, but first has to get rid of her stink. After a mean use of trickery and a brief chase, Elmyra finally captures poor Fifi.
This one was lampshaded by Fifi herself.
Fifi: "This ending stinks!"
There is, however, a popular fan theory that "Out of Odor" might be a prequel to the episode "Hare Today, Gone Tomorrow", which also shows Fifi as one of Elmyra's pets and she is rescued by Buster.
"One Beer" ends with Buster, Plucky, and Hamton driving off a cliff and getting killed as their car crashes into a graveyard. This is lampshaded by Buster at the end of the episode.
Buster: "So, do we get to do a funny episode tomorrow?"
The episode actually got pulled from syndication because of it!
"Who Bopped Bugs Bunny?"- Sappy Stanley the Elephant, a has-been cartoon star jealous of Bugs' Schloscar Award kidnaps him from an award show in Paris and even manages to frame Daffy for the crime. Buster and Babs manage to rescue Bugs and put Stanley in jail and the episode ends with the three of them flying back to Acme Acres. Happy ending, right? Except Daffy's still in jail, as are Plucky and Hamton, who got arrested trying to break the older duck out.
The Teen Titans animated series ended with "Things Change", an episode that saw long-lost ex-Titan Terra, who had previously become a stone statue at the end of her story arc, alive and living a life of mundanity. The stage seems set for a joyful reunion, but after repeated claims that she doesn't know him, "The Schoolgirl" admits that "Things were never the way you remember," and rejects Beast Boy's pleas to get her to return to the team.
Not to mention, the team never did defeat the monster they had been fighting the whole episode.
At the end of the "Total Drama Island" season 3 finale, Heather throws a pineapple into the volcano, causing it to erupt and kill almost everyone in a huge meteor shower. At the end, Heather is impaled by a giant rock.
It's not clear if that really happened, is it?
In Superman: The Animated Series, pretty much any episode with Darkseid was liable to end on one of these notes. In "Apokolips-NOW!", Darkseid's initial invasion of earth is foiled, but he shockingly kills Jack KirbyExpy Dan Turpin before leaving. Worse, the major pwning that Darkseid delivered to Superman implies that the Man of Steel will be powerless to stop him next time. In the series finale "Legacy", Darkseid brainwashes Superman into conquering earth for him, destroying his reputation with the entire human race. When Supes finally defeats Darkseid in battle, Darkseid is rescued by his own slaves, who worship him as a god, leading us to conclude that real victory over Darkseid is impossible (at least until Justice League).
Speaking of Justice League, The episode Kid's Stuff was a hilarious, light-hearted romp... until THIS exchange:
Wonder Woman: "All things considered, it was kind of nice to be a kid again!"
Batman: "I haven't been a kid since I was eight years old..." (Walks off, with everyone looking uncomfortable, then following silently)
Transformers Beast Wars ended in a bittersweet finale. Though the Maximals had defeated and captured Megatron, they suffered heavy casualties as well. The first Dinobot sacrificed himself earlier on to prevent Megatron from destroying the proto-humans. Depth Charge killed himself and Rampage in a final attempt to stop Megatron from raising the Nemesis (he didn't succeed, though he did get closure with his long-time nemesis Rampage). Tigatron and Airazor came back as one being, Tigerhawk, only to be gunned down by Megatron aboard the Nemesis in a last-ditch effort to stall Megatron. The Transmetal II Dinobot finally turned good only to die just a few seconds later after refusing to save himself from the exploding warship. Heroes aside, fans have also expressed sadness with the deaths of the Predacons as well, including Rampage, Inferno, and Tarantulas. If we're counting Transmutate, both Dinobots as separate characters, and Tigatron, Airazor, and Tigerhawk as separate as well, then Beast Wars ended with a death toll of 14 characters out of 22. That's more than half the entire cast.
The opening to Beast Machines makes this an even bigger downer ending. Not only did it turn out that they lost the beast wars, they inadvertently gave Megatron the power to conquer all of cybertron, and enacting a genocide. Of the surviving few Maximals left, two of them were kidnapped and transformed into Megatron's new generals, while the rest were robbed of their transformations and memories.
Beast Wars had numerous episodes end with the bad guys having victories, or simply leaving everyone down and out.
The episode Transmutate had the eponymous character die trying to stop its friends from killing each other, with both Silverbolt and Rampage mourning its death.
The episode "The Probe", a Maximal probe travels to Earth. The Maximals try to get a signal to it, but Megatron destroys their tower, denying them their chance to get home.
In the classicTransformers episode, "The Golden Lagoon", Beachcomber discovers a quiet, peaceful, Bambi-esque clearing filled with wildlife. A closer look reveals a lake of liquid "electrum," a gold and silver compound with the oddly useful effect of making Transformers apparantly invulnerable. He attempts to keep it to himself but the Decepticons find it anyway and proceed to let all hell break loose. Eventually the Autobots win out but it doesn't happen without the place being gutted by the ensuing chaos. At the end, all Beachcomber can do is look dejected at the ruined landscape and utter "Yeah... we won."
"Arnold Betrays Iggy": ends with Arnold mad at Iggy for forcing him to wear bunny pajamas.
"Helga and the Nanny": ends with Helga's homelife back to its regular dysfunctional state.
"The Pigeon Man": That whole episode's a Downer, but at the end, Pigeon Man loses his home thanks to the bullies who don't understand him, after he's lived as a hermit for years to avoid people like them. But the clincher is that all of his pigeons each grab a string attached to Pigeon Man and fly him away into the sunset. Make what you want of the metaphor. There is a small bit of hope since Arnold's kindness convinces the Pigeon Man that not all people are jerks who will treat him like an outcast, but it's still a pretty depressing episode from start to finish.
Futurama: many of its Emmy-nominated episodes, plus:
"Time Keeps on Slipping": Fry forced to blow up the star pattern he had meticulously created for Leela, which would apparently have been enough of a romantic gesture for Leela to finally return his affections if she had seen it. She coincidentally didn't see it because she was trying to cheer up Fry.
Also in that episode, Bender's dream is to become a Harlem Globetrotter. He fails to achieve this goal even though the rest of the crew are declared honorary Globetrotters just because they were in the right place at the right time. During the end credits, we hear Bender sadly whistling the Harlem Globetrotters' theme song.
"Jurassic Bark": Fry decides at the last minute not to resurrect his fossilized dog, reasoning that it had lived a full and happy life and Tampering In God's Domain was not wise. A final montage reveals that, in fact, the dog had spent the rest of its life pining for its lost master. The Retcon in the first movie attempts to cancel this out, but we all saw what really happened.
In "Bender's Big Score" Fry goes back in time, meaning that his dog did manage to be with him. And what's more, on 2012 (the year when he was supposed to die) Bender tracks down Fry, who is living in his old Pizzeria. He fires a laser at the building and it collapses and Fry's dog looks at it just in time for the fire and dust to instantly fossilize him. This was a bit of a Retcon, due to most fans finding the original ending soul crushingly depressing.
There was also the episode where Fry was influenced by worms to be much more intelligent and much stronger, when he blew into a hologram-creating instrument that apparently takes massive amounts of effort to play correctly and performs an elaborate and romantic image for Leela. After he decides that he'll get rid of the worms to see if it's really him or the worms that Leela had started taking to during the episode, he tries to play it again, only being able to create the image of the Frankenstein monster roaring. After Leela leaves, he sits alone, realizing that he's come up short in his romantic pursuit again.
Rocket Power - "Power Play": In the final seconds of a roller hockey game where the winner gets to play NHL stars, Twister's game tying shot at the end is disallowed.
Also, the ending of the kayaking episode where the kids were forced to clean up the Shore Shack for a month as punishment.
Two episodes that air together regularly, "Shark Bait" and "A Shot in the Park".
The Fairly OddParents - "Secret Origin of Denzel Crocker": Not quite a You Can't Fight Fate as it would've happened without him going back in time, but Timmy goes back in time to try to stop his teacher from becoming madly obsessed with fairy godparents; he successfully stops it from happening the way it did originally (it was apparently Cosmo's fault), but then accidentally ends up making it happen anyway.
And in "No Hope for Courtney", Ms. Gordon dies and Carl starts to cry at the news of this. Originally, Ms. Gordon was going to come out of retirement, but the voice actor died during production so it was rewritten that her character died as well. Since Ms. Gordon died and also her actor, you might say it's a The Character Died with Him.
In the end of the opera-themed Looney Tunes cartoon "What's Opera, Doc," Elmer Fudd has "killed the wabbit," and the dead Bugs Bunny gets up so he can do a bit of Lampshade Hanging: "What did you expect in an opera, a happy ending?" It's true: most famous operas have Downer Endings.
Averted In the Walter Lantz cartoon Flying Turtle herman the turtle wants to learn how to fly, so he gets an eagle to take him up almost to the edge of outer space, when he finally tries to fly he falls all the way to Earth, and dies in the process, however he ends up in turtle heaven, able to fly and happy as a clam.
The Powerpuff Girls, episode "Twisted Sister" has a horrible Downer Ending. The girls create a new sister named Bunny. Despite her infantile mind and hulking, Quasimodo-like physique, she learns to be a hero, saves the day, and then just randomly... explodes. Even the narrator is in tears as the episode ends. What a Mind Screw for any kid watching it.
The end of the Fantasia segment, "Rite of Spring", could be seen as a downer ending, since all the dinosaurs die. As a matter of fact, if it weren't for the Executive Meddling, Walt Disney would have kept the happier ending where a band of early humans start a bonfire and then dance in celebration of their discovery.
The last episode of Home Movies ends with Brendan accidentally dropping his beloved video camera out of the window of a car and watching it get run over and smashed by another car, after he had given up on his dream of being a film maker because he believed that his movies shouldn't be watched, despite producing impressive material for an 8-year old with a cheap camcorder.
Those of us who didn't think it was protected by the Rule of Funny thought the ending to Camp Lazlo fell under this: it looks like something's gone right for Lumpus, when it turns out he's just some looney who has the real Scoutmaster, an aged version of Heffer from Rocko's Modern Life, locked up in a closet and is dragged off to a looney bin. A person actually complained to the creator that it was a low note for a finale, so he told her that Jane bailed Lumpus out and they lived Happily Ever After in Acorn Flats... but still...
Thanks to it being unexpectedly cancelled, the Silver Surfer series ends with the Silver Surfer apparently dead and the universe destroyed.
In later seasons, South Park has grown to love this trope. Here are some examples:
The episode where Stan is forced to coach a Pee Wee Hockey team is considered one of the most miserable. One of the kids on the team has Leukemia and promised that he would live if they won a game. Eventually, they are asked to play a game at Pepsi Stadium against another Pee-Wee hockey team, but when the opposing team doesn't show up, the Colorado Avalanche volunteers them to play against the Detroit Red Wings. In probably the most cruel subversion of feel-good sports movies, if not anything ever, the Detroit Red Wings crush the poor kindergarten team by 31 to 1, all while brutally hurting many children who are less than 6 years old. When the Wings win, they have their own cliche "victory scene" while Stan's poor team is left writhing on the floor and quite a few people feeling resentment towards Stan for failing them so badly. The last shot in the episode? The child with Leukemia utters "...no hope..." and friggin dies. Okay, so winning a hockey game won't save a kid's life, but MAN was that the saddest death EVER. Made even worse by the Mood Whiplash of South Park's closing credits song.
How about the one where Britney Spears dies? It sounds funny, sure, but MAN. That was a dark episode.
"Kenny Dies": The kids spend the whole episode trying to get stem cell research allowed so they can save Kenny's life. In the end though, Kenny dies anyway, just too late. To make matters worse, Stan avoided Kenny the entire episode because he couldn't handle the idea of his friend dying. In the end he finally decides to tell Kenny he cares, and there's even a dramatic scene with him running to the hospital with balloons and a present - only for him to find out that Kenny had already passed on. Of course, this being, well, Kenny, he got better, but that doesn't make this episode any less depressing, especially when Word of God states that they'd originally intended for Kenny to be Killed Off for Real.
Made just a bit worse with Kenny's last words apparently being "Where's Stan?"
Parodied in "Woodland Critter Christmas" as a happy ending:
Cartman: And they all lived happily ever after... except for Kyle, who died of AIDS 2 weeks later.
Kyle: Goddamnit, Cartman!
Their version of Great Expectations had a very similar parody, predating the Woodland Critter Christmas episode:
"And they all lived happily ever after... except for Pocket, who died of Hepatitis B."
"Toilet Paper" had a really brutal downer ending: Kyle, riddled with guilt over the fact that he and his friends T.P.'d their art teacher's house out of resentment, was going to apologize, but unfortunately, Cartman beat him, Stan, and Kenny to the punch. Stan, Kyle, and Kenny are sentenced to 2 weeks detention, while Cartman only gets 1 for being 'honest'.
The 9th season premiere. Although, it is more of a Bittersweet Ending for Garrison, and Garrison only.
"Lice Capades" had a downer ending for both the lice and the kids. ALL of the kids were revealed to have lice, including the girls, and the louse hero lost his loved ones.
The louse hero does manage to save his baby and find refuge in a new home in Angelina Jolie's pubic hair where, it's implied, they can live happily without fear, so this one might be upgraded to Bittersweet Ending on that front.
"You're Getting Old" Stan has a falling out with his friends and his parents get a divorce. Stan sees the entire world as shit. All of this happens while Landslide by Fleetwood Mac plays, and considering the rumours floating around at the time, many critics and long-time fans believed that this was the groundwork for a series finale.
Ed, Edd n Eddy often ends with either the Eds humiliated or raped by the Kanker Sisters, and they're often funny endings, since it is a funny show. But only ONE ending actually qualifies for a Downer Ending: the ending to If It Smells Like An Ed. The Eds were accused of ruining Friendship Day, and tried to clear their names. Unfortunately, Act II has the Eds accused of bounding and gagging Jonny when actually, they found him this way. The kids refused to believe the Eds and chased them into the woods. The Eds hid in a shed, only to run into The Kanker Sisters. The cowardly three are then trapped between the kids, who are practically wishing for the Eds to die, and the Kankers, who demand the Eds to make out with them. The Eds prefered to have fruit pelted at them by the kids. It was then revealed that Jimmy, of all people, set them up. His motive? The wedgie (and subsequent humiliation) given to him earlier that day by Eddy. He then has the Kankers take the Eds away. The blow is softened somewhat after Jimmy slips on a Karma-placed banana skin, but stil...
The episode "Take This Ed and Shove It" also qualifies in a way — Eddy had just woken up from the Rip Van Winkle and declares, "I don't ever wanna grow up!" Cue Eddy waking up again, back as an old man. He soon realises that he fell asleep reminiscing about his childhood with his friends. The episode ends with him wishing he was still a kid. And this was the original series finale.
The British animated film The Plague Dogs is depressing throughout, with the story being based around two dogs who escape from an animal testing lab and try to survive in the Lake District. However, even by the standards of the rest of the film, the ending can still be considered a downer. The film ends with the two dogs being hunted by the Army, who believe that they are carrying the bubonic plague. The dogs are cornered at the beach, and try to swim to an island that doesn't really exist. It is implied that they drown.
The book's ending is quite nice, though. Read it, it'll cheer you up.
It's been suggested that the "island" in question actually is death. Because really, life's been so painfully cruel to Rowf and Snitter that death could only be a blessing.
Superjail!, of all the shows, had a downer ending in episode Mr. Grumpy-Pants where a little girl with cancer ends up in Superjail. The inmates proceed to mistake her disease as her name ("San-ser") and throw her a party, oblivious to the fact that her organs are gradually failing and she's hemorrhaging blood from her mouth during it. She proceeds to wind up strangled by the Warden's murderous inner child, and during the bloodbath between the inmates, winds up crushed by all the falling gifts for her party. The episode ends with the inmates and Alice mourning her death.
The ending of Time-Police part 1 was downbeat itself, with Alice, Jailbot, and Jared forced to leave the jail due to the Warden's absence, and realizing that they'd have to try to make it out in the real world.
The Trouble with Triples ends in a rather disturbing manner, with the Twins forcibly taken from the jail and subjected to Mind Rape by their father, with their discomfort and complaints increasing from it being "boring" to wanting to die. Up until the Snap Back anyway.
Moral Orel had quite a few episodes end on a low note, but managed to actually subvert this trope for the Grand Finale. Clay completely ruins his marriage and his affair with the coach, and his life is left in shambles, and even with Orel's upbeat happiness, he hates Clay. While Clay is a Jerk Ass, it's implied that Orel's life is pretty messed up too as his idealism is shattered. However, the subversion is that fast forward many years, and Orel grows up to raise a functional family.
In the Family Guy episode "The Cleveland-Loretta Quagmire" Loretta has an affair with Quagmire. The episode ends with the couple getting into an argument and deciding to divorce. It even gets a lampshade hanging by Peter and Lois with Peter outright refusing to accept such a downbeat ending.
Even sadder is the fact that Cleveland Jr. has been negatively affected by the split. It's part of the reason why he now looks and acts differently in the Cleveland Show.
And even more sadder episode is "Movin Out", in which Brian breaks up with his girlfriend Jillian, being probably the saddest moment in the show's history. They tried to soften this during the credits, to little effect.
"Brian Wallows and Peter's Swallows" has Brian saves a woman from committing suicide, and convinces her to go outside for the first time in years. She immediately gets hit by a car, and dies (and lives long enough for Brian to take her around the world in a virtual reality).
The final two parter of the short lived series Clone High is probably the most upsetting use of a downer ending as the entire main cast with the exception of Principal Scudworth are frozen in a meat locker just as Abe Lincoln realizes his feelings for Joan of Arc only to discover she has just slept with J.F.K. the show ends with a To Be Continued... The cancellation of this show is scientific proof that MTV blows.
The series Delta State ends on a definitive low note. After the heroes manage to recover their lost memories, vanquish the Big Bad once and for all and avert the apocalypse, Luna, who has the power of precognition, sees an alternate ending to a vision of the future she had repeatedly over the course of the series: in the original ending, the world is destroyed; in her new vision, she foresees that her and her friends will eventually be possessed by rifters, the bad guys.
Another episode "Good Neighbors" ends with Squidward's house going on a rampage due to a security accident, and Squiward is forced to work to pay off the damages done to the town every weekend for the rest of his life.
The saddest downer ending in the series is "One Coarse Meal". Mr. Krabs gets away with driving Plankton to suicuide. Worse than it sounds.
"Failsafe" ends with Miss Martian sobbing uncontrollably and the team left shaken after a training exercise goes horribly wrong. We're also left with the unsettling implication that Miss Martian may not be able to control her immense mental abilites.
The final sequence of "Misplaced" juxtaposes a shot of Zatanna sobbing over the loss of her father with another of Klarion laughing maniacally as he and his fellow villains move one step closer to completing their master plan.
The ending of "Insecurity" sees Artemis berated by her teammates for being immature and selfish, only to then be offered a chance to betray the team by her father.
The second half of the first Season of Winx Club gets many of these too. Let's see: Mirta, the first (and only) friendly witch (who's also half-fairy) gets turned into a pumpkin when she was trying to help Bloom, speaking of which, she later finds that her boyfriend is a prince and is in an arranged marriage with another girl. After finding this, depressed, she returns to Earth, where the Trix steal her powers, becoming much more powerful. With her new powers, the Trix then proceed to take over Cloudtower, summon an infernal army to conquer the world. However, things got better for every good character.
Episode 8 has Darcy successfully seducing Riven and walking away without any punishment. Stella outright says "We lost this one."
In episode 24 of season 4, Nabu dies after using up all of his energy to close the shadow abyss, and the power that could've revived him is stolen by Ogron, who wastes it on a flower. Layla ends up leaving the Winx to join the fairy Nebula's army in order to avenge Nabu's death, despite her friends trying to tell her that that is not what Nabu would've wanted.
The Gargoyles: The Goliath Chronicles episode "Genesis Undone": With the clones suffering from a genetic defect that will cause them to become stone permanently, they and the Manhattan Clan reluctantly seek the aid of Dr. Sevarius. However, Sevarius uses the Manhattan Clan's DNA not to save the clones, but to give life to his own new, improved clone, whom he refers to as his son. Some fighting later and Goliath turns Sevarius' 'son' to stone, leaving the doctor desperately pining for the one thing he had ever cared about. Meanwhile, the clones have already been permanently petrified, and there is apparently no way to reverse the process.
The episode "Metamorphosis" has Elisa's brother Derek infected with a drug that turns him into a mutant Gargoyle as part of a Dr. Sevarius experiment that supposedly not even Xanatos approved. Then Sevarius, the only one who could reverse the process, gets killed, and Derek blames Elisa and the Manhattan Clan for everything. It's then revealed that Xanatos set up everything to turn Derek into the mutant, including faking Sevarius' death. Of all the corrupt and morally questionable things Xanatos did over the series, this may be the only one that was truly EVIL. The episode ends with Elisa sobbing amongst the Manhattan Clan.
Season one of Titan Maximum ends with Gibbs succeeding at frying Mercury and killing billions of old people. The episode was titled "One Billion Dead Grandparents" after all. In the DVD Commentary, writer Matt Senreich actually invokes the trope - "Downer Ending right there. Downer Ending."
Would you believe there was an episode of Tom and Jerry ("Blue Cat Blues") that ended with them both sitting on a train track waiting to commit suicide by train? And just as it irises out, you hear the sound of a train whistle? Chilling.
There's also "The Two Mouseketeers", where the final scene is Jerry and Nibbles walking down the street. There is a drum roll and the silhouette of a guillotine dropping—on Tom's head. Nibbles replies "Pauvre, pauvre pussycat" (poor, poor pussycat) and "C'est la guerre" (that's war).
Spiderman The Animated Series has an episode that shocked us with its combination of Downer Ending and Wham Episode. Mary Jane and Peter had finally gotten married at the beginning of the season, after MJ had been lost down a inter dimensional portal and come back. They are starting their honeymoon when Hydro-Man kidnaps MJ right under Peter's nose. He manages to find her again, only for it to be revealed that both Hydro-Man and MJ are in fact clones, made from a process that hasn't been perfected yet. MJ ends up disintegrating in Peter's arms. Even worse, when you realize that this means the real Mary Jane has been floating in the interdimensional portal all this time. These two episodes left many in a state of shock for hours. The remaining 5 episodes managed to turn it into a Bittersweet Ending as Spider-Man saves reality itself from being destroyed... but Mary Jane is still missing.
Well, it was somewhat foreshadowed in that MJ's sudden return was totally out of the blue, she didn't seem traumatized by several months in interdimensional void and therefore something wasn't right. And the end of the series strongly implied that Spider-Man will find her, with Madame Web's help and all. The plan was to shoot five more episodes which would involve him doing just that, but the show was canceled.
Similarly, Spiderman Unlimited ends with Spider-Man lost in time, the symbiotes spawned from Venom and Carnage taking over the city, and everyone is apparently powerless to stop them. An ending was scripted to have them overcome the infestation and Spider-Man, Eddie Brock, and Cletus Kasady making their way back to our Earth, but the series was canceled at that point.
The Spectacular Spider-Man ends with our hero triumphing over evil. All is well, right? Well, Norman Osborn is believed dead by most of the cast and longtime childhood friend-turned-villain Eddie Brock is locked up, most likely in Ravencroft, along with John Jameson. Curt Connors has been blackmailed into leaving ESU by Miles Warren, leaving Warren to help nurture Gwen Stacy and Peter Parker's scientific skills. Mark Allen, the Molten Man, is still not in control of his power-switch, and will likely continue to be blackmailed in to doing other people's bidding. Tombstone is walking free (albeit being monitored now). The Venom symbiote is still loose somewhere in the New York sewer system. Mysterio is still running free after the one sent to prison was revealed to be another 'bot, Chameleon is still out there and Kraven is also still free to continue hunting after Spider-Man. In Peter's personal life, you have a heartbroken Liz Allen, who is too proud to show it as well as her brother, the aforementioned Molten Man, being in prison, which is no doubt affecting Mary Jane too. Possibly the biggest gut-punch though, is Peter and Gwen, who have finally told the other how they feel. It looks like they'll finally get together, until Harry takes after dear ol' dad and manipulates her into staying with him, leaving Pete alone. Damn.
Harry's dad is dead, he overheard his girlfriend say that she loved his best friend since the 7th grade (implying she never loved Harry) and his best friend said he loved her too (so his best friend stole his girlfriend, which is worse as Harryfeels inferior toPeterbecause of his dad. The only characters who don't have a downer ending are some of the villains, everyone at the Bugle except JJJ, Flash, Robbie and Sally.
Spider-Man: The New Animated Series: The Gaines Twins tricked Spider-Man into believing his long-time love Mary Jane has been murdered by Kraven the Hunter, sending him on a Roaring Rampage of Revenge, that nearly ends with Spidey murdering Kraven in cold blood. After he figures out their ploy, Spidey goes after them to rescue MJ. In the ensuing battle, the twins pull another Mind Rape on him which leads to him accidentally harming an innocent. Said innocent? Indira "Indy" Daimonji - Peter Parker's intrepid new reporter girlfriend, and one of Spidey's few consistent supporters in the series. Thinking it's Roxanne Gaines, Spidey mistakenly drops her off a roof, which the lands her in a (seemingly permanent) coma. Dozens of New Yorkers (including MJ) witness this, making Spidey Public Enemy #1, and giving J. Jonah Jameson all the ammo he needs to start a grassroots movement to run Spidey out of town. Peter is so wracked with guilt that he agrees. He goes after the Gaines Twins a final time, resulting in their deaths (and nearly his) via explosion. The next day, Mary Jane tries once more to rekindle things with Peter, relating her sympathy over him losing Indy and being let down by Spider-Man. Peter manages to reject her in an even more heartbreaking manner than the first movie, barely being able to look her in the eye. Harry has his hatred of Spider-Man "justified" after seemingly turning a corner when Spidey helped save Sally from Electro. To top it all off, Peter locks the suit in a brick-laden case and tosses it into the river. Given that the series was cancelled after this, it seems that Spider-Man's quest to honor his Uncle Ben has ended in an even worse failure than "The Night Gwen Stacy Died." So, to recap - Spidey "loses" MJ (TWICE!!), nearly MURDERS Kraven, puts his new girlfriend in a coma, has the entire city turn against him, basically kills the Gaines Twins, and is abandoned by the one person that needed him the most - PETER PARKER. This HAS to be the most depressing depiction of Spider-Man ever committed to the screen.
In "The Sad Story Of Henry/Come Out, Henry!", Henry the Green Engine was afraid of the rain and has refused to come out of the tunnel, And everyone tried to get Henry out of the tunnel, And nothing worked. Eventually, Sir Topham Hatt gave up and punished Henry by having the construction workers taking away the rails from Henry and build a brickwall so that no one can bump into Henry, Now Henry is very sad because he believes that no one will ever see his green paint with yellow stripe again. Very sad.
In "Dirty Work/Diesel's Devious Deed", which doubles as The Bad Guy Wins, Diesel told lies to the troublesome trucks that Duck made cruel names about Gordon, Henry, and James. The three big engines found out about the trucks' teasing and turn on Duck. Even the Fat Controller was suspicious of him. As a result, Duck is sent to Edward's station as a punishment while Diesel smirks triumphantly of his plan.
In "Thomas Comes to Breakfast". Thomas burst into someone's house where a family was going to have breakfast. The mother got angry at Thomas for ruining their breakfast so she slammed the door. And the plaster fell everywhere, including Thomas. Despite Donald and Douglas pulling Thomas back on the track, The Fat Controller lectured to Thomas that he got into a lot of trouble. And now, that the Diesels will have to do the work for Thomas. The last shot of the episode is completed with Percy and Toby laughing at Thomas.
Adventures of the Galaxy Rangers had a couple of Bittersweet Ending episodes that veered plenty bitter. The pilot episode "Phoenix", for one. The Hero Zachary Foxx is gunned down and paralyzed, only to be fitted with experimental cyberware, the Big Bad is loose in the galaxy and has a few dozen humans hostage after a successful attack on a League Planet. The privateer still has Zach's wife. The only good parts are that the kids escaped (though Mandell's original pilot had them captured as well), and that BETA authorized the Ranger team to strike back.
ReBoot loved these after getting Darker and Edgier. Web World Wars ends with Bob exiled in the web and Megabyte in position to take over. Game Over ends with Enzo losing an eye and the game resulting in everyone thinking he's dead. System Crash ends with Phong explaining that despite their hard work, Mainframe is still doomed. Then comes the cliffhanger in season 4, where Megabyte has taken over the Principal office.
The Danny Phantom episode "Public Enemies" ends with Walker essentially winning, having managed to turn almost the entire town of Amity Park against Danny (including Jack and Maddie now viewing him as a threat to be destroyed) and labeling him as the main cause of ghost attacks. Sure, Walker gets sucked back into the Ghost Zone at the end, but it's only because Wulf sacrificed his own new-found freedom to do so.
In Iron Man: Armored Adventures, a HUGE one comes in "Ghost in the Machine" - Ghost steals the specs to the Iron Man armor AND finds out that Tony is Iron Man. Afterwards, he sells the specs to Stane AND Hammer. To top it all off, Ghost plans on blackmailing Tony when he gains control of the company and Tony can't do anything to Ghost because he made it so if anything happens to him, Tony's identity goes global. Also, Tony didn't patent his armor. Big downers all around.
The 2 Stupid Dogs episode "Red Strikes Back" - the duo once again encounter Red Riding Hood, she blissfully ignores her grandma's cries for help as she's yet again devoured by the wolf, and encounters the witch from Hansel and Gretel who notices her and the dogs munching on her house; she takes Red inside and forces her to eat a ton of food. Once she grows wise to the witch's plan to eat her, she kicks her and attempts to escape, but the witch uses her powers to trap her in a cage; she then imprisons her and the dogs and summons food for the dogs to feed Red. Two years pass and Red is very obese; the witch turns into a frog and eats her, after which she then informs the dogs that she's still hungry. The dogs try to persuade her not to eat them and they tell her that they just want some cheese; she summons some easy cheese and sprays it on them and she shadow engulfs them and we hear chomping and gulping sounds. In the ending title card, it shows them and Red inside her stomach surrounded by the digestive acids.
The first episode of season 2 of My Little Pony: Friendship Is Magic ends with Discord having successfully broken and brainwashed almost the entire main cast except for Twilight Sparkle, pretty much destroying their friendship in the process. He tricks Rainbow Dash into breaking the rules of the game via a Sadistic Choice, handing himself victory in his little "game". The episode ends with Twilight Sparkle watching in shock as Discord lets loose a storm of chaos on Equestria. Sure, things get better next episode, but that was still a very bleak way to end an episode!
"A Canterlot Wedding, Part 1" continues this tradition, ending with Queen Chrysalis, impersonating Princess Cadance, lulling Twilight into a false sense of security before magically imprisoning her within the crystal caves beneath Canterlot.
When the Wind Blows, the main characters survive a nuclear bombing, but are obviously dying of radiation poisoning. They remain in denial with complete faith that help will arrive and save them. Even in the end they have a semi-optimistic tone, but have clearly given up as they crawl into their paper bags and into their shelter to die. Then again Raymond Briggs (the original author of the book the film's based on) never did like happy endings that much. He just writes what he thinks seems natural for the situation, I mean take a look at The Snowman at the end!
Episode 26 of Scooby-Doo! Mystery Incorporated. The Freak of Crystal Cove turns out to be Fred's dad, the Mayor, who we now learn isn't Fred's dad at all and was trying to find the supposed treasure of Crystal Cove. Fred had proposed marriage to Daphne, but that's now in indefinite abeyance as he's out to find his real parents and who he really is. Velma is now on everyone's sh*t list for not coming clean about Angel Dynamite's real identity (original Mystery Inc. member Cassidy Williams), Shaggy is getting sent to military school, and Scooby is being sent to a farm. Original Mystery Inc. mascot Professor Pericles has made off with both segments of the Planispheric Disc (telling the whereabouts of the treasure), and the episode—and season—ends with Scooby vowing to hunt down Pericles and reunite the gang.
The season 2 premiere is as much a downer as the season 1 finale. The gang—save for Daphne—has reunited at Crystal Cove's beckoning because of a creature called Crybaby Clown. Fred's trap to capture him fails because Daphne, who now has a new boyfriend, was not at the position he called for. Fred's confidence is shattered as Crystal Cove is left in Crybaby Clown's destructive wake, and Velma assesses that the city will hate them even more.
Then there's episode 37. Cassidy forms and uneasy alliance with the gang to trace the origins of Germanic robots that tried to kill her earlier in the episode. They (along with 1967 H-B stars Tom, Tubb, Scooby the seal and their Moby Dick submarine) find their way to an underwater city that was the original Crystal Cove settlement. The show's villain, previous Mystery Inc, mascot Professor Pericles, is the culprit and before escaping he sets off detonation charges. Cassidy stays behind so the rest can escape in the sub, but a shattered diving helmet and the official word from producer Tony Cervone is that Cassidy did not survive. The episode ends with the gang mourning Cassidy.
American Dad! did one where Steve fails to reform Roger's alter-ego Ricky Spanish. Ricky frames Steve for a theft and he gets sent to prison, crushing his innocence and naivete. The sad voice over by Werner Herzog doesn't help.
The episode "Hot Water" ending with the evil hot tub (voiced by Cee-Lo Green) killing Principal Lewis and the salesman and eating Francine, Stan tries to save Francine but he ends up being thrown out the window where he lands on top of a truck where he finds a spray can that would kill the hot tub, but before he can use it Stan dies of internal bleeding, this was originally intended as the series finale before the series was renewed.
Adventure Time has this happen more often than it should. Most prominently in I Remember You, which simply ends in tears (both the character and the audience) and features one of the most cruel and brutally honest examples of Reality Ensues ever, and The Lich (notably, a season finale), which ends with the heroes discovering that they just did exactly what the Big Bad wanted them to.
One of the best-known examples of this trope in the show is the episode "Too Young". At the end, Princess Bubblegum is forced to return to her original age of 18 to stop the Earl of Lemongrab's tyrannical rule over the Candy Kingdom. Finn is devestated, especially when PB claims not to remember her time as a 13-year old. The show's fan community exploded in outrage after the episode aired, with many threatening a boycott.
The ending of "Frost & Fire" certainly qualifies. At the end, Finn writes fake letters to Flame Princess and Ice King, each written from vice versa's point of views, to have them fight, because when they fought earlier it caused Finn to have exciting dreams about it, and it's also very important as welll because the Cosmic Owl is in it as well. After he completes his dream, he reveals the truth to Flame Princess and Ice King. The results: Flame Princess is so hurt and depressed she possibly dumps him (How depressed, you may ask? She can only hear Finn's attempt of an explanation as "waa waa waa"s), and the Ice King just says "Pssh, you BLEW it, man!". The Flame Princess dumping scene also leads to many a "Funny Aneurysm" Moment if seen after such episodes with Finn and FP bonding, such as "Vault of Bones" (the aforementioned episode aired after "Frost & Fire" premiered, adding further insult to injury). Then in the next episode, "Too Old", Finn went back to attempting to win Princess Bubblegum's heart one last time, and realized Flame Princess was the one for him, but Jake ominously stated she might have moved on. The arc may be concluded with the episode "Earth & Water".
"The Eyes": "I'm...still not happy."
How about every episode of Johnny Bravo. What sucks is that the series finale is included. Johnny gets famous after Shaquille O'Neal believes him to be good luck around whenever he plays. Unfortunately Johnny leaves Shaq to use the bathroom when it really matters, and Shaq does good without him, leading him to the realization that Johnny didn't really create luck, and Johnny goes to drown his loss with Seth Green and Huckleberry Hound.
In The Proud Family, a lot of episodes had pretty depressing endings. Such as when the songs available for downloading on the Internet wind up making a man's CD store close down, and it ends with him sobbing while closing up for good. Or when Suga Mama finds out the man she was going to marry had Alzheimer's and was taken away from her.
Downfall of a Droid: Although Anakin is saved by Ahsoka, R2-D2 is still missing and in the hands of Gha Nackt, who is delivering R2 to Grievous, and R2 is assumed DIA (Destroyed in Action), and now nobody cares about R2, except for Anakin. It still counts as cliff-hanger as the events continue into "Duel of the Droids".
The Zillo Beast Strikes Back: The Republic is forced to use lethal gas on the Zillo Beast killing the creature to save Coruscant, and it was the last of its kind. Though it may also qualify as a Bittersweet Ending, considering they saved Coruscant from destruction. Ends on something of an unresolved Cliff-hanger after Palatine's intentions to clone the beast are revealed.
Heroes on Both Sides: The peace attempt ends in failure as the Suicide bomber droids destroy the power generator of Coruscant, convincing pretty much every senator to defeat Padme's peace with the Separatists bill (They can't make peace, because it's Doomed by Canon).
Counter Attack: Anakin and Obi-Wan's team failed to escape the Lola Sayu Citadel because their one way ticket out of there, their shuttle, is destroyed, along with ARC Trooper Echo. They now require a fleet of Republic ships to escape the planet.
Padawan Lost: Kalifa is dead, Ahsoka is still trapped on Wasskah, and she is being hunted by Garnac for killing his son, Dar (in self defense). The final shot of the episode is Anakin alone and sad, still unsuccessful in locating Ahsoka, possibly to the point of giving up and abandoning her. (Even though he said "I'll find herů") (Thank heavens the next episode aired along with the final episode of Season 3, Wookie Hunt, which kind of makes it less tragic, especially with Chewbacca involved.)
Gungan Attack: The Republic/Mon Calamari/Gungan Military Force (including Anakin, Padme, Jar-Jar, Kit Fisto, Ackbar, and Senator Tills) is defeated and captured by Riff Tamson's forces; the Separatists and Quarren are triumphant, and only Ahsoka and the Mon Cala prince, Lee-Char, are the only ones that are not captured. Sure, things get better in the third act of the next episode, but that was still a very bleak way to end a season premiere!
Darkness on Umbara: Nowhere near as harsh as Slaves of the Republic or Gungan Attack and not so much a downer as is a dire predicament, but still pretty relevant. Fives and Rex and their troops end up fighting another mob of Umbarans after pushing them back, which is where the episode ends.
Slaves of the Republic ends with our heroes thwarted in their escape from Zygerria and are separated. Ahsoka is imprisoned above the Zygerrian queen's palace and is being tortured mercilessly by Atai Molec. Obi-Wan and Rex, along with the Togrutan governor of Kiros, Roshti, are sent to Kadavo, and submit to the Zygerrians after the warden, Keeper Agruss, drops several slaves to their dooms; and Anakin is now the Zygerrian queen's personal slave and guard on Zygerria and is left thinking if he would join the queen willingly in exchange for the freedom of his friends. In other words, the attempt to locate the colonists has failed, and we assume that no one is coming to rescue our heroes. The ending is made even more tragic by the fact that the last part of the story arc, Escape from Kadavo, didn't air till January 6th, 2012! (Arguably one of the biggest downers of the series!) Sure, things get better next episode, but that was still a very bleak way to end a first half of a season!
A Test of Strength: Although the attack on the ship was successfully averted, Ahsoka has been kidnapped after being knocked into Hondo's ship. Hondo then has her knocked out and plans to use her as profit, since he didn't get the lightsaber crystals. The younglings are left on their own, drifting on a heavily damaged ship.
The Amazing World of Gumball often has Downer Endings Palyed For Laughs in many eipsodes...save for The Finale, in which the revelation of the Watterson's various misadventures turning out to have had long term consequences on Elmore rather than things suddenly being back to normal by the next episode, and now the Wattersons owe various people around town thousands of dollars. When the family is unable to cough up enough money and wind up in jail, they decide to enact the series' Reset Button by really messing stuff up. This only makes things worse and levels the town, and the final shot of the episode is the The Wattersons surrounded by the enraged denizens with the unsubtle indication that they are about to be beaten to death. To make matters worse, this would have been the Series Finale had the series not been renewed.
Green Lantern: The Animated Series episode "Loss" has a definite downer ending. Razer, who seems to be overcoming the death of his wife and ready to start a life with Aya, can only watch as Aya get blasted by the Anti-Monitor's anti-matter Wave Motion Gun after she pushes him out of it's path. He's then forced to watch her die in his arms as he tearfully begs her to live, and that he loves her.Fixed after Aya turns up alive (in a Man-hunter body)in "Cold Fury" only to bond with Anti-Monitor's body at the end and continue what he started after Razer reconsiders what he said.
The Sym-Bionic Titan episode "A Family Crisis" ends with Octus, part of the main trio, dead. Lance angrily blows up a Mutraddi base in response, not that it helps them.
The Motorcity episode Vega: ends with Mike having been captured by Kane, with his execution being planned. Motorcity is now in shambles due to KaneCo bots running amok without the Burners able to help.
The ending of the Recess episode "Omega Kids". The entire school except for the workers and T.J.'s gang is sick after eating Tuna Fish Tacos. At first, the gang really likes being the only ones there, but it all spirals downhill after Ms. Grotke says they should catch up on some work. To prevent them from doing work, the gang pretends they are sick, but the fake sickness they have turns out to be so severe that they can't be sent home. The episode ends with them trapped in a plastic dome with several people in hazmat suits barracading the school.
Captain Planet and the Planeteers has "Whoo Gives a Hoot?" The Planeteers attempt to stop Looten Plunder with a court injunction against clear-cutting an old growth forest where an endangered species of owl lives. They fail and the episode ends on that note, with Plunder taunting them to try and stop him again.