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. However, the exact reproductive method 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 threatens Dana, they overpowered him.