Homunculuses are deformed, child-like monsters that can only appear in Chapter 4 commonly.
They're usually attached to walls with "umbilical cords". Homunculuses can be seen sleeping at first, but as soon as entering the room where the creatures located, their eyes will open and heads start shaking. Afterwards, they'll try and run to Isaac.
Given enough time, it will detach from the wall, shooting 6 blood shots, and chase after Isaac quickly. They'll leave a small amount of red creep after death if either still attached to the wall or detached.
- They will still leave creep behind when using the D10 item.
- Using the "Death" tarot card will prevent them from leaving a trail of red creep after being killed.
- 4 Homunculuses always appear during the Mr. Fred boss fight. Not free at all, but they can be only detach by Mr. Fred's command.
- A homunculus is a small human-like creature from sixteenth century folktales.