-121061695This article refers to both the original game and the remake.-119875774
IsaacHDIsaac Rebirth

Loki (ロキ Roki), also known as "Baby Demon" and "Fetus Demon" in the artbook, is a boss found in the Depths.


He resembles a red demon Baby with four arms, small horns, and The Mark on his forehead. He also has a smile with large fangs.


His main attack has three steps. He makes poses whilst attacking. First, he shoots 4 projectiles in a plus shaped pattern, followed by 4 shots in an X shaped pattern, and finishing with another 4 shots in a plus-shape pattern. His other attack shoots 8 projectiles in a circle around him.

He also randomly teleport himself during the fight.

He is sometimes assisted by a single Poky. At times, he may summon Boom Flies to accompany him, which can damage him upon exploding.

Champion Variant


Eternal Loki

Eternal Loki uses all his bullet-related attacks 3 times in a rapid session, while summoning normal Babies and Angelic Babies (though they look like their Eternal variants). He also can heal himself for 10% of his max HP every time Isaac takes damage.


  • It is rare to find him as a boss. He is, however, very common in Sheol (encountered in pairs) and sometimes can be encountered in The Womb. He can be encountered in triplicate in The Chest.


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Loki in the Artbook.

  • During developement, Loki's codename was "Mr.Cool".[1]
  • It was confirmed by Edmund on Formspring that Loki indeed possesses two pairs of arms.
  • In Norse mythology, Loki is the god of mischief and chaos.
  • His Japanese name, "Roki", translates to "deadlines".


TBoI information

The Binding of Isaac

Loki is a boss encountered in The Depths and Necropolis.



Loki as seen from Isaac's Last Will.

From this version, Loki's Boom Flies does get damaged by Pokies.


The Binding of Isaac / Rebirth
Regular bosses Original: BlastocystChubDuke of FliesThe FallenFistulaGeminiGurdyLarry Jr.LokiMonstroPeepScolex
(Wrath of the Lamb: Daddy Long LegsGurdy Jr.Mask of InfamyPinWidow)

Rebirth: Dark OneDingleGurglingsThe HauntMama GurdyMega FattyMega MawMr. FredPolycephalus
(Afterbirth: BrownieDangleLittle HornRag ManTurdlings)
(Afterbirth †: Big HornRag Mega)

Posthumous Bosses Original: Monstro II
(Wrath of the Lamb: The Blighted OvumThe BloatCarrion QueenThe HollowThe HuskLokiiTeratomaThe Wretched)

Rebirth: The AdversaryThe CageThe Gate
(Afterbirth: The ForsakenThe FrailThe Stain)

Alternative Bosses Original: C.H.A.D.GishSteven
(Wrath of the Lamb: Triachnid)

Rebirth: Sisters Vis (Afterbirth †)

Harbingers Original: WarFamineDeathPestilenceHeadless Horseman

(Wrath of the Lamb: Conquest)

Final Bosses Original: It LivesMomMom's HeartSatan
(Wrath of the Lamb: ???Isaac)

Rebirth: The LambMega Satan
(Afterbirth: HushUltra Greed)
(Afterbirth †: Delirium)

Seven Deadly Sins EnvyGluttonyGreedLustPrideSlothWrath
Seven Super Deadly Sins Super EnvySuper GluttonySuper GreedSuper LustSuper PrideSuper SlothSuper WrathUltra Pride
Angels / Demons Original: Krampus

Rebirth: GabrielUrielFallen Angels

The Legend of Bum-bo
Regular bosses BygoneDuskGibsGizzardaLoafPeeperPyreSangreShy GalThe Duke
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