Rhonda is a walrus who works for Dr. Blowhole. She appeared in the episode, Roomies.
She is Agent 12 and was sent by Dr. Blowhole on a class F freighter to get Kowalski's plasma cutter. She was Marlene's disgusting roommate (Who was secretly a spy), that was seen farting, blowing mucus out of her nose without a tissue and singing "Take me out to the ballgame" which only irked Marlene. She thought Marlene was a rat at first and called her rat face.
She was sent from the Hoboken Aqaurium to live with Marlene. She weighs 1500 lbs and is very fat, annoying, disgusting and obnoxious. At the end of the episode she is seen with Kowalski's plasma cutter heading for the Hoboken aquarium, in NJ possibly going to meet Dr. Blowhole.
She also appears in The Hoboken Suprise. Like all of the animals at the Hoboken Zoo, she is imprisoned by Francis Alberta and replaced with a happy android duplicate. She later helps the animals escape by launching Savio, and all of the animals in his belly, out of the hole created by Skipper. She somehow escapes herself and participates in the battle against the android duplicates. It is unknown if she is still a spy for Blowhole.