Rot is a mutant potato. Like most mutant potatoes, Rot loves mud. He plays games in it, he eats it, he even sleeps in it! So, when Rot sees the most magnificent, messy mud pit ever, he can't wait to dive right in.

But then, Rot's big brother warns him: Watch out for the Squirm! The Squirm is slippery and slimy and gross and grimy, and it lives in the beloved mud. Now, Rot's too scared to jump into the puddle. Can anything help him feel brave enough to take the plunge and face...the Squirm?