Cougar

When Wiggum, Lou and Eddie are alerted about a possible intruder in the Springfield Mall after closing time, one of the methods they use for finding said intruder is a cougar.

The animal locates Bart and Milhouse and chases after them. They fend him off with a ball of wool and he returns to the police who believe he has caught a rat (not realizing it's a string of wool). Lou and Eddie ask how they should get the cougar back in his cage but Wiggum just brushes off his hands saying their job is done.