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.
Eternal Champion Behavior
Despite the normal Embryo is harmless, the Eternal Embryo is definitely the opposite. Eternal Embryo is much larger than an ordinary Embryo (roughly 10x), and shoots intense rings of blood shots in short session. It can also "duplicate" itself - spilting into 2 smaller Eternal Embryos. It's capable to spilt multiple times, and the smaller ones can still shoot rings blood shots.
- 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.
- In the original game, Embryos have a Boss Health Meter due to them being the final stage of Blastocyst and therefore the game counts them as a boss.