Shrewtooth

Shrewtooth is this skinny as itch who's afraid of his own shadow. For revenge, he slaps people with his butt because he was slapped by Twolegs. It is not know if it was a butt or something else. He poops in the river because he's afraid that Twolegs with find his poop and clone him and become a robot like Firestar was. So the poop gets washed away so the Twolegs or anything else can't get to it.