Sheldon is a genuine military fanatic from a well-respected family who is fascinated with his weapons. He has developed nearsightedness due to staying up late every night tinkering with weapons and small parts, causing him to be rejected from the military for his extremely poor eyesight. Undaunted, he decided to start a business selling weapons out of his own home, and Booyah Base was eventually built on the same land upon which that home stood. However, it was not Sheldon but his grandfather, Ammoses Shellondorf, who owned the land.
Despite him and Bisk both being crabs, they look quite different from each other.