"If brains was lard, Jethro couldn't grease a pan."
- Jed Clampett
Jethro Bodine was the lovable but dumb as a rock nephew of Jed Clampett on the CBS sitcom The Beverly Hillbillies. Max Baer Jr. played Jethro for all 274 episodes (106 black & white, 168 color plus a 2 hour sequel) for the duration of the television show, 1962 to 1971.
Jethro's shit-eating grin, redneck ways, silly schemes to constantly reinvent himself (as a hippie, millionare playboy, movie star, brain surgeon and "double-naught spy" among others) and 6th grade education endeared his character to audiences, helping to make The Beverly Hillbillies the most popular sitcom in TV history. He easily towered over the other characters on the show (Max Baer Jr. was 6' 4") and was as dumb as he was strong, eating like a pig and chasing every attractive woman in sight. In June of 1966, Jethro finally earned his grade school diploma, although he never quite got the hang of ciphering.
Jethro's immediate family played a pivotal role in the development of the series. His mother, Cousin Pearl Bodine, suggested Jed move to Beverly Hills in the first place. Jethro's sister, Jethrene Bodine (also played by Max Baer Jr.) had a part during the first year of the show.
i got some of this info from all over the web and from my own recollections of the show