History Characters / TheBindingOfIsaac

A list of characters who appear in the ''VideoGame/TheBindingOfIsaac'' franchise. Currently under construction, please contribute!

After beating It Lives, the Cathedral is unlocked. At the end of the Cathedral resides Isaac himself... and one of the toughest challenges in the game.

* TheBusCameBack: The original Mom's Heart form, to an extent, in ''Afterbirth+''. While unlocking It Lives used to make it so that you can no longer fight Mom's Heart, ''Afterbirth+'' lets you fight Mom's Heart again in the Void, likely so that the Bestiary is completable for those who already unlocked It Lives.

* BattleThemeMusic: Its first phase shares "''Ascension''" with ??? (because according to Edmund, it ''is'' ???), before it transitions to the heavier and oppressive "''[[https://www.youtube.com/watch?v=rbflsmpA69c Morituros]]''" when Hush's true form emerges.

** [[spoiler:However, ''The Legend of Bum-bo'' implies in its final ending that Dad was not the abusive one. He gave well-intentioned advice to Isaac about fueling his imagination to help cope with reality, and claimed that he will always be with Isaac in spirit.]]

->Debut: ''Afterbirth+''
A mysterious new character who debuted in ''Afterbirth+'' and was unlocked by default prior to an update in which they are unlocked by killing Mega Satan for the first time. He starts with the new Void item, which destroys and copies the effects of activated items while turning passive ones into random stat boosts. Apollyon is the Greek name of (and he therefore represents) Abaddon, the angel of destruction and the abyss in Revelations, the last book of the Bible.

->Debut: ''Afterbirth+''

The Forgotten is a skeletal character added in the fifth Booster Pack for ''Afterbirth+''. He has a melee attack and uses a special type of "bone hearts," and can switch to a ghost called the Soul, which plays similarly to the Lost and is chained to the Forgotten. All red hearts become bone hearts and are given to The Forgotten. All soul and black hearts go to The Soul. He is unlocked by assembling a special shovel and using it on a room late in the game.

''Afterbirth+'' (Soul Sucker)

''Afterbirth+'' (Mr. Red Maw, Mr. Mine)

''Afterbirth+'' (Crispy)

''Afterbirth+'' (Stoney, Cross Stoney)

''Afterbirth+'' (Leper)

''Afterbirth+'' (Dank Charger)

''Afterbirth+'' (Tube Worm)

-> Debut: ''Afterbirth+''

''Afterbirth+'' (The Thing)

''Afterbirth+'' (Blister)

''Afterbirth+'' (Ministro)

''Afterbirth+'' (Poison Mind)

''Afterbirth+'' (Gush)

''Afterbirth+'' (Nerve Ending II)

''Afterbirth+'' (Tar Boy)

-> Debut: ''Afterbirth+''

-> Debut: ''Afterbirth+''

-->Debut: ''Afterbirth+''

--> Debut: ''Afterbirth+''

->Debut: ''Afterbirth+''

->Debut: ''Afterbirth+''

->Debut: ''Afterbirth''
->Debut (Ultra Greedier): ''Afterbirth+''

->Debut: ''Afterbirth+''

The final boss of an area added in ''Afterbirth+'', the Void. Beating Hush will unlock a floor made up of various different environments from the game, with this as the boss of one of its several boss rooms. It first appears to be a giant, melting skull, but will shift forms to white variations of the previous bosses.

[[quoteright:100:https://static.tvtropes.org/pmwiki/pub/images/sucker.png]]

* DisasterDominoes: In a room with several Spits, killing one while standing in the right direction will often cause a chain reaction of vomit bombs that kill the rest of them.

* AllYourPowersCombined: The I. Blob's projectiles, which are a combination of the other two.

* EliteMooks: The I. Blob variant shoots projectiles in all eight directions.

!!Stone Grimace/Vomit Grimace/Gaping Maw/Broken Gaping Maw/Turret Grimace/Stone Eye/Brimstone Grimace/Cross Grimace
[[quoteright:240:https://static.tvtropes.org/pmwiki/pub/images/grimace.png]]

!!Boil/Gut/Sack/Gush/Walking Boil/Walking Gut/Walking Sack
[[quoteright:144:https://static.tvtropes.org/pmwiki/pub/images/boil.png]]

!!Fred
[[quoteright:100:https://static.tvtropes.org/pmwiki/pub/images/mrfred.png]]
-> Debut: ''Wrath of the Lamb''
* BodyHorror: It's based on a baby with [[http://en.wikipedia.org/wiki/Harlequin-type_ichthyosis Harlequin-type ichthyosis]].
* WhackAMonster: They pop up in random areas of the room and attack either by firing an explosive shot or shooting a spray of bullets while diving through the air, before going underground and repeating the process.

[[quoteright:100:https://static.tvtropes.org/pmwiki/pub/images/lump.png]]

!!Brain/Poison Mind/Black Globin's Head/[=MemBrain=]/Guts/Scarred Guts/Mama Guts
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/brain_0.png]]
-> Debut: ''The Binding of Isaac'' (Brain, [=MemBrain=], Guts, Mama Guts)\\
''Afterbirth'' (Scarred Guts, Black Globin's Head)\\

* AsteroidsMonster: [=MemBrain=] and Mama Guts splits into two Brains and Guts respectively when killed.
* BodyHorror: Does a sliding brain or rolling ball of organs sound pleasant to you?
* OrganAutonomy: Quite literally, they're organs that move on their own.

* ObviousRulePatch: The Broken Gaping Maw exists in only one room, for only one purpose; because the room used to house four standard Gaping Maws in the centre, and a player character with flight and sufficiently low speed could become trapped forever in the centre of their combined gravity. The Broken Gaping Maw shuts off periodically, allowing the player to escape. Booster Pack #5 made them far more ubiquitous.

[[quoteright:230:https://static.tvtropes.org/pmwiki/pub/images/gaper.png]]

!!Mr. Mine/Mr. Maw/Mr. Red Maw/Swinger
[[quoteright:136:https://static.tvtropes.org/pmwiki/pub/images/mrmaw.png]]

* AsteroidsMonster: Depending on whether you kill it by shooting it in the head or "body", Mr. Maw will spawn a Maw or Gusher, Mr. Red Maw a Red Maw or Gusher, and Swinger a Maw or Globin. Averted with Mr. Mines, which only fires six shots in all directions upon death

[[quoteright:210:https://static.tvtropes.org/pmwiki/pub/images/mulligan18.png]]

[[quoteright:100:https://static.tvtropes.org/pmwiki/pub/images/charger.png]]

* DeadlyLunge: If they spot Isaac, they will open their mouths wide and speed towards him... exactly like Chub does.

!!Round Worm/Nightcrawler/Roundy/Ulcer/Tube Worm
[[quoteright:230:https://static.tvtropes.org/pmwiki/pub/images/roundworm.png]]

[[quoteright:226:https://static.tvtropes.org/pmwiki/pub/images/trite_5.png]]

''Afterbirth'' (Rag Man's Ragling, Blister)

!!Fistuloid
-> Debut: ''Afterbirth+''
* BodyHorror: As the name implies, it's a tiny Fistula.
* KaizoTrap: Fires a maggot towards Isaac on death.

!!Pacer/Gusher
[[quoteright:100:https://static.tvtropes.org/pmwiki/pub/images/pacer.png]]
-> Debut: ''The Binding of Isaac''
* EliteMooks: Gushers to Pacers.
* HighPressureBlood: Gushers shoot out a fountain of blood from their necks, but only the occasional blood shot can actually deal damage.
* OverdrawnAtTheBloodBank: Gushers, as the name implies, have a constant stream of blood flowing from their necks.

[[quoteright:114:https://static.tvtropes.org/pmwiki/pub/images/skinny.png]]

* EliteMooks: The versions with one eye are faster and have more health. Their meat pile also [[{{Knockback}} slides away diagonally]] a short distance to avoid being hit.

!!Brain/Poisoned Mind/[=MemBrain=]/Guts/Mama Guts
[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/brain_0.png]]

* GoodCounterpart[=/=]TokenHeroicOrc: He's a Keeper monster who's on Isaac's side, and his combat style is identical to that of that of Greed.
* GlassCannon: By default, he has above-average damage and a triple shot. Just giving him some fire rate boosters makes him dish out pretty decent damage. However, he is usually never more than two hits away from death, with special items like Holy Mantle (and its weaker trinket counterpart the Wooden Cross) and Greed's Gullet being the only ways to extend that.

** It's possible to extend his life with a few items. A Swallowed Penny or the Piggy Bank drop coins in battle if he gets hit, which will retore his health if picked up. Meanwhile, Greed's Gullet is the only item capable of extending his health above the maximum by picking up coins and ''never spending them''.

* TheCameo[=/=]MythologyGag: A smaller version of [[VideoGame/MeatBoy Larrie's Lament]].

* TheCameo[=/=]MythologyGag: Steven is from ''VideoGame/TimeFcuk''.

* TheCameo[=/=]MythologyGag: C.H.A.D. is a boss from ''Super VideoGame/MeatBoy''. Dropping the item Little C.H.A.D. on defeat references his post-fight cutscene from the above.

* TheCameo[=/=]MythologyGag: From a game with the same name, ''VideoGame/{{Gish}}''.

* TheCameo / MythologyGag: Originally appeared as bosses in Edmund's earlier game, ''Gish''.

* TheCameo[=/=]MythologyGag: Triachnid is a reference to a previous flash game by Edmund [=McMillen=]. Furthermore, Triachnid is an alternate of Daddy Long Legs; in his own game, Triachnid was finding a home for his young.

* TheCameo[=/=]MythologyGag: From Creator/EdmundMcMillen's flash series ''Dead Babies''.

* HeartIsAnAwesomePower: His unlockable starting item is merely [[spoiler:a six-sided dice]]. Many players agree that it is among the best starting items in the game regardless, since it rerolls any spacebar items in the room into random ones.

* BadassNormal: He's the only playable character that starts off without any sort of supernatural assistance. Even [[spoiler:the D6]] is merely [[spoiler:a six-sided die]].
* BaldOfAwesome: Being a young child, he has no hair normally. It doesn't hinder him at all.
* BoringButPractical: In both the Flash and ''Rebirth'' versions, he starts with a single bomb. It seems like nothing, but it guarantees you'll be able to blow up a marked rock (and get DMG up and/or Soul Hearts) should you encounter one, or take a shot at finding a secret room.
* HeartIsAnAwesomePower: His unlockable starting item is merely [[spoiler:a six-sided die]]. Many players agree that it is among the best starting items in the game regardless.

* DeadAllAlong: [[spoiler:After beating It Lives for the tenth time and unlocking Ending 10, Isaac comes across his corpse stuffed into a chest. At least one interpretation of this involves Isaac having been dead the whole time. The next three endings explore the events leading up to his death in reverse chronological order, first showing him willingly [[DrivenToSuicide locking himself in the chest]], then showing his self-loathing which led to this, and finally showing his [[DarkAndTroubledPast tragic backstory]] through a heartbreaking PhotoMontage. After beating Hush in ''Afterbirth'', if you end your run there, not going on to Cathedral or Sheol, you get Ending 17, which outright confirms it, as Mom opens the Chest to find Isaac's skeletal remains.]]
** Ending 20, the true ending to the game, reveals that [[spoiler:he has long since been DrivenToSuicide and that none of the game is even happening]].

* BigBad: [[spoiler:Ultimately subverted.]]

** In ''Afterbirth+'', you can unlock a starting Speed Up pill for her through the challenges. Not flashy, but useful since she starts out with reduced speed.

* CastFromHitPoints: The Dead Bird is activated by taking damage in a room and works as a faster level three Meat Boy for the room in which it activates.

* DealWithTheDevil: While holding the Book of Belial, the chances of a Devil Room appearing are increased. Unfortunately, Judas' starting 1 heart makes it impossible to make deals unless he gets more heart containers or soul hearts, or buys an item that grants him black hearts.

* TheUnpronouncable: With a name like ???, his FanNickname (Blue Baby) was inevitable.

* PowerupLetdown: He's probably the most difficult character to unlock in the original (with [[spoiler:???]] possibly being more tedious than difficult), as it requires you to pass on 2 free items on a regular run... and its capacity is dubious, to say the least. After months of complaints, Edmund promised a buff to Samson. The buff was starting with a soul heart on top of his single regular heart. He became much more useful in ''Rebirth'', as he now starts with three regular hearts and his buffs from killing enemies and taking damage remain until you leave the floor. On the other hand, now you have to clear two floors in a single run without taking any damage to unlock him, which is arguably even more difficult.

* CrutchCharacter: Despite his low range, Azazel's flight and high damage make him by far the easiest character to play as. However, he plays entirely differently from every other character, meaning that playing with him doesn't build the skills you need to be good with the rest of the characters. In addition, many items have no effect on his short-range Brimstone, so he's locked out of a lot of neat synergies.

* TookALevelInBadass: ''Afterbirth'' gave him the potential to start with the D4 and the Holy Mantle. Plus, he gained spectral tears.

** Keeper's starting items aren't available [[MagikarpPower until you unlock them]], and they're mundane at best. The Store Key trinket only opens access to shops, whereas the Wooden Nickel has a chance to fail, as seen in LethalJokeItem below, and he only starts with a bomb (and a penny when you unlock it).

* EliteMooks: The Evil Twin. Instead of looking like a meat puppet, it looks like a demon that can: fly, shoot a triple-shot and do more damage. Thankfully, its bullets travel slower, giving you time to dodge and shoot.

* BulletHell: Its attack patterns during its second form. They even resemble the dense ring-patterns found in ''danmaku'' shooters like the ''{{Franchise/Touhou}}'' games.

* TakenForGranite: Ultra Greed turns into a solid gold statue when killed. Midas' Touch (touched enemies temporarily turn into gold) destroys his damage scaling property, letting you deal greatly increased damage. In Greedier Mode, he keeps attacking as a statue and explodes into a fine gold dust on death.

* DefeatMeansFriendship: [[MindScrew It's not clear whether or not they're the same entity]], but upon defeating Delirium for the first time, the player unlocks Delrious (spawns friendly bosses on their Delirium form to fight for Isaac) and Lil' Delirum (shapeshifts into one of a handful of different familiars and wins its effects).

* ThenLetMeBeEvil: [[spoiler:It is strongly implied that at the ending of ''Rebirth'', Isaac becomes a demon or TheAntichrist in order to deal with all the horror he went through, up to and including his mother.]] [[spoiler:Ultimately subverted, as this is how he sees himself, for, in his own mind, being the reason his father and sister "left forever".]]

* TimedMission: Played with. If you want to guarantee access to the Void and thus to Delirium, you have to beat Hush, which means you need to beat It Lives before the 30 minute mark (or have Mama Mega! on that floor). That said, the portal to the Void has a chance to spawn after beating Mom or any subsequent boss, increasing as you go further. Mega Satan has a 50% chance at best. He's also the only boss for whom completion is tracked even on victory laps, however, so one valid strategy is to take your time gathering items on the first run, defeat The Lamb, and then speedrun through the victory lap with your items to reach Hush.

* OurGhostsAreDifferent: The ghost that spawns during its second phase, which bears a resemblance to The Lost.

* CantLiveWithoutYou: Dying as the Forgotten or the Soul is GameOver, regardless of the health of the other party. However, it is possible to kill the Soul through a Devil Deal and survive if you swap back to the Forgotten during the ItemGet animation; if you do this, the Soul will be disabled until you collect a Soul/Black Heart to restore it.

* DiscOneNuke: His flight and Brimstone are a major advantage in the early game, and flight remains an important bonus throughout. However, his limited range will really begin to catch up to him when it comes time to face endgame bosses.

* HitAndRunTactics: Unlike others who depend on kiting with tears, Azazel often has to fly in, blast several enemies with brimstone, then get out of there before the rest retaliate. He can also strafe multiple enemies for the duration of his Brimstone but again he has to be closer than normal for tear-strafing.

* TheLastOfTheseIsNotLikeTheOthers: At the time of his release, Azazel was by far the most different from the other playable characters, since he starts with miniature brimstone instead of tears, has evil hearts (but can gain red ones, unlike [[spoiler:???]]), and has flight (which only [[spoiler:The Lost]] shares). The result is a rather different playstyle, including item selection, since his smaller brimstone makes many items useless/redundant but others extremely powerful.

* RequiredSecondaryPowers: At the time, a melee character would've been an interesting addition to the roster, but an actual melee attack would make multiple rooms UnwinnableByDesign. Azazel being equipped with the piercing brimstone and flight fixes both of these problems. A true melee character eventually came along in the form of [[spoiler: The Forgotten]] with its own set of RequiredSecondaryPowers.

--> Eden isnt a man, nor are they a woman.. they just are. %%[sic], directly copied from http://bindingofisaac.com/post/86958618769/spoiler-alert-you-unlocked-eden -- I don't know if it's policy to correct such quotations or not.

A ghost character, and one of the only characters not based off of any sort of religious context[[note]]unless it refers to the "souls lost in Limbo"[[/note]], next to ???. It is the secret character of ''Rebirth'' and had a '''very''' complicated unlock process... until ''Afterbirth'' came along.\\

In Rebirth, The Lost starts with Flight but [[OneHitPointWonder dies if he takes any damage]], with the inability to ever pick up health. ''Afterbirth'' significantly buffed The Lost, granting him spectral tears and The D4 by default, as well as letting him unlock Holy Mantle, giving him a shield that blocks one hit per room.

** ''Afterbirth'' ''vastly'' simplified the unlock process; you just need to die in a Sacrifice Room while holding the Missing Poster. Of course, nowhere in the game does it tell you this, and the fact that the former method is much better known doesn't help.

** Its lack of HP means that it can take Devil items (some of the most powerful items in the game) for no cost at all; normally, it would cost one or two heart containers for one of those items. This can lead to VERY powerful combos, turning it from a joke character into a feasible GlassCannon if you get multiple deals with the Devil in a single run.

* UselessUsefulSpell: Once you unlock the Holy Mantle for the Lost, the D4 becomes this, simply because the ability to actually take a hit per room outweighs just about anything it can potentially be rerolled into. A large portion of the items in the game also falls into this category, namely any item that gives only health and anything that activates on taking damage.

* WhamShot: ''Afterbirth'' adds a new, interesting loading screen. That voice that told Isaac's Mom he was evil? It was the Lost, speaking from the attic.

Named after Adam's first wife who defected from Heaven with Samael. She's also known as the "The Mother of Demons." Unlocked in ''Afterbirth'' after clearing Greed Mode with Azazel. Starts out blindfolded, meaning she is unable to shoot tears, but also starts with the Incubus familiar whose tears have the same properties as hers, the Box of Friends active item which duplicates her familiars for one room, and the Cambion Conception passive item which permanently grants a new familiar upon taking a certain amount of damage.

* AwesomeButImpractical: Some of the Cambrion Conception minions are extremely good, like Brimstone Baby or Dark Bum (!!), especially when doubled with Box of Friends. You'll need to take at least 15 hits ''per minion'' though, which is easier said than done with Lilith's starting health.

* MagikarpPower: If you can pick up more familiars or find a way to spawn at least one more with Cambrion Conception without dying, Box of Friends' effectiveness begins to multiply. Gaining boosts to spacebar charge rate increases how often she can double her army of minions, and BFFS just makes everything stronger.

* MookMaker: Playable variant. Lilith starts with Cambrion Conception which permanently spawns a new demonic buddy after taking enough damage by giving birth to it, if the progressively more and more pregnant appearance is anything to go by.

A character unlocked by the efforts of the community in the ''Afterbirth'' [[AlternateRealityGame ARG]], Keeper is the corpse of Isaac that kills himself by hanging. He becomes playable by donating 1000 coins to the Greed Machine. His name refers both to the shopkeepers he resembles and to Cain's words in the book of Genesis, "Am I my brother's Keeper?" He starts with a triple shot, is healed by pennies, and cannot pick up hearts. Hearts he is given become Blue Flies.

* GoodCounterpart / TokenHeroicOrc: He's a Keeper monster who's on Isaac's side, and his combat style is identical to that of that of Greed.

** Instead of hearts, Keeper has two coin slots (and can only have a maximum of two); any kind of damage takes a health coin (which still counts as red heart damage for the purposes of Devil/Angel Room generation), but taking another coin on the floor heals it back '''without''' increasing your coin count. This means that Curse Rooms (without Holy Mantle) and two-heart Devil deals will straight-up kill him, while one-heart Devil deals leave him as a OneHitPointWonder. All health increasing items are worthless unless you've lost one coin slot already. He also can't take soul or black hearts, as they get converted into flies.

** In Greed Mode, Keeper effectively gets hearts every wave that can be picked up mid-combat provided the player is fast enough. The only downside is that doing so decreases the money available to buy pickups and items. This extends to Ultra Greed's battle; since his attacks make you drop coins on contact, you just keep getting health back, and since Ultra Greedier attacks generate coins during the fight, you'll never run out short of gross incompetence.

* MagikarpPower: [[DownplayedTrope Downplayed]]. He's a difficult character to play as, but by defeating certain bosses as Keeper, you can get some mundanely useful starting items for him (and a single dumb penny), making him... still pretty difficult to play, but at least a little better. He's much more useful in Greed Mode, as he rapidly build up coins and heal back any damage taken. The Wooden Nickel item

* PowerOfTheVoid: A successful Apollyon run depends in big part in judicious use of his Void starting item, which can turn into an all-powerful item and/or give Apollyon massive stat increases by the end of the run.

* DemBones: Well, he ''is'' a skeleton. The special bones hearts he uses (which become available as drops for all characters after he's unlocked) take three hits to deplete and can be refilled with red hearts, but are lost forever if they're destroyed.

* MundaneUtility: The Forgotten's melee attack can be used to open spiked chests without taking damage. Furthermore, hitting anything with the melee attack counts as touching it for the purposes of collection, which can be used to grab collectibles (but not items) from behind rocks or over short pits. This is normally redundant with the Soul's flight but can come in handy if the Soul is disabled.

** LethalJokeCharacter: Since his health can only be composed entirely of soul and black hearts, he can exploit certain health-based mechanics (such as the Whore of Babylon, which is permanent if picked up), leading to quite a few potential and powerful combos. He also has permanent access to Devil and Angel Rooms, snce he's not taking red heart damage.

* MechanicallyUnusualClass: Tamer than later examples, but his restriction on hearts makes quite a few items work very differently for him as noted. Most health ups are bad, but anything that gives soul hearts is exponentially more powerful.

** In Wrath of the Lamb, Bloody Lust makes Samson powerful... if you manage to survive the hordes of enemies that give him his strength. Only having a single heart (later a soul heart as well) makes that easier said than done.

* NotQuiteDead: His gimmick is being able to resurrect instantly, rather than outside the room he died (forcing him to restart it).

* CloseRangeCombatant: Until [[spoiler: The Forgotten]], he was the closest thing that ''Rebirth'' had to one, since his starting weaponry forces him to get relatively close to enemies. He compensates by possessing above-average speed and flight.

** As it turns out, [[spoiler:this trope is played ''literally'', with the revelation that the entire game is Isaac's DyingDream.]]

* DarkAndTroubledPast: The horrible memories of things that Isaac suffered through are relived in level loading screens. In one ending, the photograph montage of Isaac's past leaves a lot of interpretation as to what happened to his family, namely what happened to his father (who likely left, went missing, or died).

--> “[[spoiler:Isaac... who were you talking to?]]"

* TheUnfought: Isaac never encounters God in-game. Even when going to a cathedral, the boss of that is Isaac himself, and the floor after that is not another holy location so much as it is a chest where Isaac's postmortem counterpart lies.

* AlcoholicParent: [[https://i.gyazo.com/7719e028341e1e6bb1afd49d4994b855.png The Dad's Lost Coin card]] in the Binding of Isaac: Four Souls is an Alcoholics Anonymous chip.
* DisappearedDad: Right from the beginning of the game, the intro states that Isaac lives alone with his mother. [[spoiler:The final ending implies that something happened which caused him to leave in anger and drove him from Mom, and by beating the BossRush as The Forgotten, you unlock the ''Divorce Papers''. Notably, the Dad's Key item lets Isaac open any door [[note]]even the one leading to Mega Satan[[/note]] -- in other words, leave the given room he's in.]]
* TheGhost: Justified considering the game's setting. He's already out of the family, and Isaac instead wanders the Basement fending against demons. [[spoiler:However, even as it becomes clear that the gameplay is set in a DyingDream, Dad himself is never directly encountered.]]
* GreaterScopeVillain: Subverted; [[spoiler:he is mostly responsible for the deranged setting and monsters that Isaac encounters, but he only created them in the hopes that Isaac would learn to use his own imagination as a coping mechanism.]]
* UnwittingInstigatorOfDoom: [[spoiler:''The Legend of Bum-bo'' reveals that he (at least partially) created the "world" that both it and ''The Binding of Isaac'' take place in, with the intention of teaching Isaac to rely on his own creativity in order to deal with the stresses of reality. Unfortunately, Isaac becomes too delusional with the mental world he and Dad formed together, and ultimately chooses to commit suicide instead of moving on with life.]]
* WalkingSpoiler: Plays a part in the game's overall lore, but is not really hinted at doing so until around unlocking the Polaroid/Negative, which takes over a dozen playthroughs assuming no skipping involved with items, buttons, or Error/Black Market rooms generating trap doors. Or by going through Hush and Delirium and seeing Ending 20, since it is possible yet difficult for newer players to beat that path before unlocking either photograph. ''The Legend of Bum-bo'' takes it even further by revealing Dad's true significance in the setting of both games.

* WhamLine: In the true ending, Bum-bo talks about making his "kingdom" and expanding it, filling it with adventure, [[spoiler:until his voice suddenly changes, and reveals that his kingdom was made for Isaac and that "Bum-bo" was in fact his father, who did it all to help Isaac escape the stresses of reality.]]

* GoodWingsEvilWings: Both are possible, though not at the same time -- Angel items for the "good" variant, and Devil items for the "evil" ones.

* ItemGet: Holds up new items -- [[TooDumbToLive even in battle]]. You're not invincible when that happens, either.

* NoNameGiven: His surname is never known in-game. When ''Four Souls'' [[https://twitter.com/edmundmcmillen/status/1027346682227257351 confirmed Mom's name,]] his last name would logically be Moriah -- the mountain in the Biblical story of Isaac. [[spoiler:The only hazy part is whether or not that's Mom's maiden name, and whether she and/or Isaac have it after Dad left.]]

** Guppy, activated by picking up three Guppy items, transforms the player character into Isaac's pet cat. Doing so unlocks a new item (the first time), gives you flight and applies a buffed version of the Mulligan that spawns a fly upon every hit.

* OurGhostsAreDifferent: The ghost that spawns during its second phases, which bears a resemblance to The Lost.

A list of characters who appear in ''VideoGame/TheBindingOfIsaac''. Currently under construction, please contribute!

[[folder:Bum-bo]]