Mr. "Thumbs" Tanner is the Stoolbend High School wood shop teacher. True to his nickname, only his thumbs are intact, while his fingers are just stumps.
When Cleveland Jr. finds he is in danger of failing wood shop and is afraid of disappointing Cleveland in "Little Man on Campus", after seeing that his father has turned to cheating, Cleveland decides to replace his name on Ernie Krinklesac's project resulting in an "A" grade. Cleveland finds out that he is the cause of Jr.'s misdeeds and pulls Holt from the game.
After Cleveland shows him that cheating isn't the answer he comes clean and gets an F but Donna uses her position as school secretary to change his grade to a "B".
Mr. Tanner is voiced by Glenn Howerton.