Mutie (aka the Cute Mute) is a character featured as part of the foamy fan special episodes. They are not listed as official episodes so they may not contribute to the canon established in the universe of the numbered episodes.
Her real name is Joanna. She is a friend of Germaine's from back when she was thin and had hair who slept over when she drank too much at a party. and met Foamy. Foamy went to buy her a Jelly cookie and Germaine wanted it.
Like her nickname, she does not speak, and may actually be a mute. Like Germaine, she meditates in a lotus position. Foamy describes her as more focused than Germaine. She has blonde hair, blue eyes and enormous breasts. She has pink lips (probably lip stick) and wears a voluminous pink dress.
She is not deaf, as Foamy imagines at first, but rather has very good focus. She laughs at Foamy's joke about nuts, whereas Germaine has never laughed at Foamy's humour before.