Allopotamus is a mutant Allosaurus that had the hind legs and nose of a hippo. He has appeared throughout the series as a background character. He also most likely has the same creation origins as the Radioactive Dinosaur-Spider, since both have DNA from theropods.

  • In "The Mutants who Cried Monster", he was seen reading the newspaper.
  • He was also seen in "Sugar Low" during the chase scene between Peri and Mister Smarty Smarts.
  • He is mostly seen up close when the whole town starts screaming