The maggot-like creature is a character from Don't Hug Me I'm Scared 3 that cracks out of an egg intended for Yellow Guy. He shouts "Father!" and is immediately crushed by Duck Guy's flyswatter, calling him a "pesky bee."
The maggot shares a likeness with Shrignold, who has a similar abdomen and antenna.
Possibly, this is a metaphor for abortion.