The Egg Monsters were a group of aliens originating from Mars that appeared in Egg Monsters from Mars. They are described as resembling a pile of rotten scrambled eggs with eyes. Despite their appearance, they are benevolent creatures. The eggs arrived on Earth during a meteor shower that only hit the protagonist's town.
Not much is known about them except for a few facts:
- They seem to be more awake and alert when exposed to cold frigid temperatures.
- They have the ability to communicate through synchronized swarming.
- They are sentient enough to understand other languages even though they have yet to speak any.
- They can reproduce with other beings. Though the precise nature of how is unknown. As Dana had no idea he was impregnated by them until the very end of the book.
- Despite their grotesque look, they are benevolent and protective to those that show kindness to them. When Dana was nearly freezing to death, they formed a warm blanket to protect him and when Dr. Gray attacked Dana, they overpowered him.