Enemies:

(Flies)
Black Fly
Attack Fly
Motor
Eternal Fly
Pooter
Fat Fly
Boom Fly
Red Boom Fly
Sucker
Spit

(Spiders)
Spider
Big Spider
Trite

(Environmental)
Boil
Gut
Sack
Walking Boil
Walking Gut
Walking Sack
(Mulligan & Friends)
Mulligan
Mulligoon
Mulliboom
Hive
Swarmer

(Hopper & Friends)
Hopper
Flaming Hopper
Leaper
Pacer
Gusher
Gaper
Frowning Gaper
Gurgle
Mr. Maw
Horf
Maw
Red Maw
Psychic Maw
Globlin
Gazing Globlin

(The Knights)
Knight
Selfless Knight
Mask + Heart
(Clotty & Friends)
Clotty
Clot
I. Blob

(The Maggots)
Maggot
Charger
Spitty

(The Body Parts)
Brain
MemBrain
Guts
Mama Guts

(General Womb Enemies)
B. Licker
Para-Bite
Fred
Lump

(The Leeches)
Leech
Kamikaze Leech
Holy Leech
(The Host)
Host
Red Host

(Vises)
Vis
Double Vis
Chubber

(Non-Living)
Poky
Slide

(Eyes)
Eye
Bloodshot Eye

(Twins)
Dople
Evil Twin

(The Babies)
Embryo
Baby
Angelic Baby

(Keepers)
Keeper
Hanger

(The Grimaces)
Stone Grimace
Vomit Grimace

(Special)
Champions