For the monster from The Legend of Bum-bo, see Gaper.

Gaper (ぽかんと口を開けて見とれる人 Pokanto kuchi o akete mitoreru hito) are monsters only appearing in Chapter 1.


They are children that resemble Isaac, but have blood instead of tears, a smile, and paler skin.


Gapers will attempt to walk towards Isaac by taking the most direct route possible, and deal damage by contact. If there is no way to reach Isaac, due to obstacles such as Rocks or Poop blocking the way, they will stand still and avoid moving towards Isaac until a proper route is created. They can be also seen with Frowning Gapers in pack.

On occasion, they can turn into Pacers or Gushers after dying.

Eternal Champion Behavior

Eternal Gaper acts the same as the original one, but it moves a bit faster and always turns into Eternal Horf or Eternal Gusher upon death.


  • They can be spawned by Mom.
  • A pair of Gapers may appear at the beginning of the boss fight with Monstro.


  • They appear in the original game.
  • The word "gaper" is a person who stares, typically in amazement or wonder.
    • Its Japanese name "Pokanto kuchi o akete mitoreru hito" translates to "People who admire and gaping mouth open".
  • The Gaper, Mulligan, Hive and Swarmer are all the same monster in stages of decay and infestation. The Gaper seems to be the fresh corpses, before decay sets in.[1]


Black FlyAttack FlyMoterEternal FlyPooterFat FlyBoom FlyRed Boom FlyDrowned Boom FlySuckerSpitDart FlySwarm FlyRing FlyLevel 2 FlyFull FlyHush FlyBall of FliesSpiderBig SpiderTriteRaglingRag TriteLevel 2 SpiderTicking SpiderBaby Long LegsCrazy Long LegsWall CreepBlind CreepRage CreepPara-BiteCod WormScarred Para-BiteRound WormNightcrawlerRoundyUlcerMaggotChargerSpittyConjoined SpittyDrowned ChargerGrubClottyClotMega ClottyLeechKamikaze LeechHoly Leech
BoilGutSackBlue BoilHostRed HostWall HuggerSlidePokyStone GrimaceVomit GrimaceGaping MawTurret GrimaceBrimstone Grimace
MulliganMulligoonMulliboomHiveSwarmerNestDrowned HiveHopperFlaming HopperLeaperPacerGusherSplasherGaperFrowning GaperGurgleMr. MawFlaming GaperCyclopiaSkinnyRottyNullGreed GaperBlue GaperSwingerHorfPsychic HorfGlobinGazing GlobinBlack GlobinDank GlobinKnightSelfless KnightFloating KnightBone KnightBonyBlack BonyFattyFlaming FattyConjoined FattyBlue Conjoined FattyPale FattyKeeperHangerVisDouble VisChubberCage VisScarred Double VisHomunculusBegottenDopleEvil Twin
Body parts
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