Scaredy Rat Stack
From the Super Mario Wiki
Scaredy Rat Stacks are a type of enemy appearing in Paper Mario: Color Splash. A stack of Scaredy Rats form when multiple Scaredy Rats group up, forming a stack. They only appear as a 10-Stack, and their health is represented by the number of Scaredy Rats left in the stack. One Scaredy Rat Stack appears in Toad Trainworks.