Monsters vs. Aliens Wiki
General information



Mutant grub


Shooting silk



Behind the scenes
Voiced by

Conrad Vernon



Feature film

Monsters vs. Aliens


Mutant Pumpkins from outer Space


Insectosaurus is one of the main characters of the movie. According to both The Art of Monsters vs. Aliens and character designer Craig Kellman, Insectosaurus is female. Before transforming into a butterfly with feminine characteristics, she was mistakenly believed to be male by the Missing Link.

Insectosaurus was originally a one-inch (25.4 mm) grub who was transformed by radiation into a 350-foot (106.68 meters) tall monster that attacked Tokyo. She was captured in 1969 and formed a close bond with the Missing Link, who is the only person that can understand her. She transformed into a butterfly in 2008.

Insectosaurus originally was nothing more than a simple grub with no unique characteristics, but after her mutation, she donned an almost mammalian-like appearance similar to that of an orange hamster with a massive overbite, four pincer-like arms, antennas, two stubby feet, and a short reptilian-like tail. Insectosaurus is a massive creature in size even dwarfing the giant Ginormica. She is seen in the movie using her powerful pincers to pull the bridge back in place in the Golden Gate fight seen. Not only can she do that, she can also shoot sticky web substances from her nostrils that were used only on the Alien Robots eye to stop it from reacting for a short time so the other Monsters could get her and Ginormica (Susan Murphy) to the Golden Gate Bridge. She walks in a dinosaur-like fashion and is very slow. Sometimes she doesn't know what to do so she is mesmerized and navigated by a helicopter carrying a light. When that happens, the pupils of her eyes grow.

After metamorphosing near the end of the film, Insectosaurus' appearance is changed to that of a more butterfly-like creature (similar to Mothra of Godzilla fame) while still possessing a hamster-like face, furry body, massive overbite and reptilian-like tail. She is accordingly renamed to Butterflyosaurus.

In Super Brawl 3

Insectosaurus makes a cameo on the Monster Bay stage, destroying a bridge.


  • She believes the Missing Link to be her father.
  • The relationship between Link and Insectosaurus might be a parody of the film King Kong vs. Godzilla.
  • Their friendship served as the basis for Sta'abi and Vornicarn.
  • When Insectosaurus was cut from the series, B.O.B. took her place as Link's best friend.
  • Insectosaurus's backstory is vastly similar to Godzilla and other Kaiju.