Ms. Mouse

Ms. Mouse is a mouse who seems to be Itchy's girlfriend.

History
In "The Glass Moan-agerie", after Itchy blows Scratchy into a glass "NO VACANCY" sign for a motel, he sits in the hot tub with Ms. Mouse and admires his work. While Ms. Mouse and Itchy admire the sign, Scratchy shouts, "No!" every time the sign lights up.