Mr. and Mrs. Kroker are both the parents of Kif Kroker. Amphibiosans go though stages of their life, and Mr. and Mrs. Kroker are both colonies of flying hookworms, because they are in the last stage of the Amphibiosan circle of life. Amy's mother, Inez Wong once squashed a part of Mr. Kroker's body at Amy and Kif's fonfonrou ceremony. She was then told by Kif of his species' life cycle and learned from him that she hit a piece of his father. After apologizing to Mr. Kroker, she states that whatever she hit would grow back with all the bugs in the area. Mr. Kroker. stated "That was my left testicle !" leading to a state of awkwardness for both families much to the amusement of an observing Bender.
- "The Beast with a Billion Backs" (debut)