Boss Monstro
Found In
The Basement
Boss Challenge Room
Boss Rush
Normal Enemy (Later Floors)
Dropped Items
Boss Pool

Monstro is one of the bosses that appears in The Basement. He is amongst the most common to fight, particularly because he can appear on later floors as an enemy.


It's worth noting that Monstro's tears do damage when they are close to the ground, though difficult to tell.

  • Two enemies can spawn alongside Monstro, either of them have a chance to be champions.
  • He will upchuck a large amount of tears, The larger tears do one heart of damage.
  • When Monstro lands after jumping off-screen he will shoot out more tears, from which the large tears also do one heart of damage.
  • He will also hop towards the player, in an attempt to crush them.

Champion VersionsEdit

Red: Two smaller Monstros have replaced the one big Monstro. They too, can spawn with a variety of normal enemies as well.
Dark Grey: Uses tear volleys much more often than the normal Monstro, but will never jump off-screen.


  • Monstro appeared in the original Binding of Isaac.
  • Monstro is missing a tooth.
  • Monstro is Portuguese for Monster.


Bosses Boss Monstro
Basement MonstroGeminiDingleLarry Jr.The Duke of FliesGurglingsFistulaStevenFamine
Cellar Gurdy Jr.PinWidowBlighted OvumThe HauntDingleLarry Jr.The Duke of FliesGurglingsFistulaFamine
The Caves ChubGurdyGurdy Jr.Mega MawMega FattyDark OneC.H.A.D.Pestilence
Catacombs The HollowThe HuskPeepPolycephalusThe Carrion QueenThe WretchedDark OnePestilence
The Depths The CageMonstro IIThe AdversaryThe GateLokiGishWarMom
Necropolis The BloatThe Carrion QueenMask of InfamyThe WretchedThe GateLokiWarMom
The Womb Mr. FredScolexTeratomaMama GurdyThe BloatLokiiDeathConquestMom's HeartIt Lives
Utero BlastocystDaddy Long LegsTeratomaMama GurdyThe BloatLokiiTriachnidDeathConquestMom's HeartIt Lives
Sheol The FallenSatan
Dark Room The LambMega Satan
Cathedral Isaac
The Chest ???Mega Satan
Devil Room Krampus
Angel Room Angel
Levels 1-5/7 The FallenThe Headless Horseman
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