Growing tired of his son's weak nature, Great Grandfather Pines forced a young Stan Pines into boxing lessons, hoping it would build a stronger character. Though Stan believed it was done simply because his father disliked him, he later grew to appreciate the lasting benefits, later repeating the same process with his great-nephew, Dipper Pines.
From what little we hear of him from Stan, it's implied that he was tough, but fair; only pushing Stan so he would be the best he could be. He also seems to be a man of few words, as in all his time onscreen, his only reaction to his surroundings is a simple nod of the head.
- 119. "Dreamscaperers" (flashback, no lines)
- 212. "A Tale of Two Stans" (flashback)