Like most of the SquarePants family members, Sherm is square, and has pores. He has several buck teeth, pants like SpongeBob, a bow tie, brown eyes and has a watermelon in his nose.
In the episode Stanley S. SquarePants, Sherm sends his son to SpongeBob's house due to his inability to hold down a job, and that fact that he is irresponsible, and that he ruins everything he touches. Sherm took away several privileges of his adult son, in which Stanley has referenced by telling SpongeBob that his father never allowed him to watch TV, or touch the refrigerator or toilet.
He was born one of at least six children of Grandma and Grandpa SquarePants. His siblings are Blue SquarePants, Harold SquarePants, and at least three unnamed brothers. His childhood home may have been Grandma SquarePants' House, but this is unconfirmed.
When he became an adult he married an unknown wife. They had a boy named Stanley S. SquarePants.
Sherm apparently never lets Stanley do anything because of Stanley's destructive nature. At some point, he had enough and sent Stanley away to SpongeBob's house to be straightened out. Although it has not been shown, it can be implied that Stanley went home or at least left SpongeBob's house since Stanley hasn't been seen since his debut episode Stanley S. SquarePants.
At some point, Sherm put a watermelon up his nose and got a picture taken of it.
Sherm is mentioned various times in the series in the episodes Krab Borg and Stanley S. SquarePants, but is never seen except briefly in Pest of the West when SpongeBob shows a picture of him with a watermelon sticking out of his nose.