I hate manure.
~ Buford "Mad Dog" Tannen's last words, though those were the same words said by his descendant Biff Tannen with the same dislike.

Buford "Mad Dog" Tannen is the main antagonist in the film Back to the Future Part III. An outlaw living in the latter half of the 19th century, he lived around Hill Valley, California. Tannen was the great-grandfather of Biff Tannen.

He is portrayed by Thomas F. Wilson.


Tannen was nicknamed Mad Dog because of his temper and his tendency to drool. Tannen, however, hated the nickname and reacted violently when people called him that to his face. Tannen was a notorious criminal who had shot at least 12 men, "not including Indians or Chinamen." Later generations would have a hard time verifying that claim since Tannen had shot the local newspaper editor after the man had printed an unfavorable article about him.

Sometime in 1885, Tannen approached Doc Brown to shoe his horse. Doc Brown did so, but then Tannen failed to pay for the job. The horse later threw his shoe while Tannen was riding him. As a result Tannen was thrown from his horse, along with a bottle of whiskey. Tannen would later demand Doc pay him $75 for the horse, and $5 for the whiskey, totaling $80. Doc offered to re-shoe the horse, but it was too late since Tannen had shot the horse. Brown refused since Tannen never paid him for the original job.

In the original timeline, Tannen murdered Emmet "Doc" Brown by shooting him in the back. Doc Brown was buried by his girlfriend Clara in a cemetery on the outskirts of town, she had it noted on his stone that he was shot in the back over a matter of $80.

70 years later, in 1955, when Marty McFly discovered Doc's fate, he went back to 1885 to save Doc, and upon arriving in Hill Valley soon meet Tannen. Tannen nearly killed the youth, but Marty was saved by Doc Brown. Marty would later return the favor at the town festival when he kept Tannen from shooting Doc. It was at this festival where Tannen called Marty chicken and challenged him to a shootout at 8:00 Monday morning. Marty accepted, thinking he would be gone by then.

Train delays and the capture of Doc Brown by Tannen forced Marty to face the gunslinger. Taking a cue from a Clint Eastwood film, Marty wore an iron furnace door under his outer clothing. This saved his life and enabled him to defeat Tannen, erasing the tombstone that sent Marty back to 1885 from history when Tannen's head cracked it in two.

Beginning a family tradition, Tannen fell into a cart full of manure as law enforcement arrived to arrest him for robbing the Pine City Stage.

Buford Tannen's last words were later used again by his great-grandson Biff in 1955 with the same hatred of manure passed onto him.


  • He most likely inspired Marshal Nathan Van Cleef from the Owen Wilson/Jackie Chan movie Shanghai Noon.