John Winfield Stephenson (August 9, 1923 – May 15, 2015) was an American actor, most active in voice-over roles. He has also been credited as John Stevenson. He was also known for voicing Tom Cat & Jerry Mouse in 1975 The Tom and Jerry Show. He worked in the animation business (particularly Hanna-Barbera) beginning in the early 1950's, with some of his most recognizable characters being Mr. Slate from The Flintstones, Doggie Daddy from Augie Doggie, Captain Murphy from Sealab 2020, General Flagg and Col. Sharp from G.I. Joe: A Real American Hero, Professor X from Pryde of the X-Men. and Alpha Trion, Bosch, Devcon, Huffer, Kup, Thundercraker and Windcharger in The Transformers. Stephenson never gave any interviews and was rarely seen in public, although he did make an appearance at BotCon 2001.