Embryos are one of the weakest monsters that appear in Chapter 1 and 4. They are Blastocyst's last stage types.
They are small, humanoid-like creatures with round heads and lack entirely of limbs.
Embryos are completely harmless. They hop around aimlessly and never target Isaac, but can still deal contact minimal damage. This enemy can spawn on any floor and is usually met in a room with a Blood Donation Machine.
- An embryo is a multicellular diploid eukaryote in an early stage of embryogenesis, or development.
- Embryos bear a strong resemblance to Spewer, the character of the game Spewer which was also created by Edmund McMillen.
- Embryos use the same death sounds as gooballs from the game World of Goo.
- From the original game, unlike other common enemies, Embryos have a health meter, which is to make players, who have yet to face Blastocyst, wonder why they do.