Cletus Klump is Sherman's father. He is crude and a bit dimwitted, as shown by farting at the table, even in front of Carla, and insults Grandma Klump. In the second film, he has erectile dysfunction and tries to cure it with Sherman's youth formula.
Anna Klump is Sherman's mother. She is kind, doting, and proud of her son.
Ernie Klump is Sherman's brother. He frequently calls Sherman "Joe College" and has a surly demeanor. He also has a son, Ernie Klump Jr., who is the only member of the family not played by Eddie Murphy (instead, Jr., who rarely says a word, is played by Jamal Mixon). Both Ernies tend to be amused when Cletus farts at the table. Jr., in fact, is the most amused by it.
Grandma Klump is Sherman's oversexed grandmother. She is very open about her sexuality and tries to seduce Buddy Love in the second movie. She also dislikes Cletus and insults him frequently.