The Mutant frog is one of Dr. Animos former Mutants that first appeared in Ben 10.
The Mutant frog looks alot bigger then normal. He has two long horns sticking on either side of his head where his ears should be. He has four big red eyes and is all green with orange dots.
Being a frog this creature can jump very high. He also has an extremly large tounge which was used against Dr. Kelly.
He first appears in Washington B.C. to help Dr. Animo attack the landlord. He also seems to be the mutant that always helps him get away.