Jerry is the new husband of Jenda Simpson.
History
Not much is known about Jerry, only that he married Jenda Simpson some time after her divorce from Bart. He became the Step-Father of Bart's children, who seem to like Jerry, but also maintain a good relationship with their actual father. He is some sort of stramge Alien-Insect hybrid life form, which was probably discovered in the future of which he is seen in.
He seems to have a neutral relationship with Bart, even though Bart is never enthusiastic to see him, or him with Jenda; but if Bart and Jerry have no conflicts and they are friends..
He states that he has to visit the gym often to keep in shape, or else he will make a strange alien noise, for no apparent reason.
He left Jenda briefly after she brought him a new tank to shed his skin, it's possible he requires a tank to live in.
