In Back to the Future 1, 2 and 3, we get to see all sorts of versions of Biff Tannen. 1955 young Biff, 1985 middle-aged Biff, and 2015 old fart Biff. The old fart version is pretty harmless, being bullied by his grandson Griff, but still able to figure out how to operate a time machine he's never been in or seen before.
In #3, we meet Mad Dog Tannen of 1885, as well. Griff and Mad Dog are two crazy, out-there versions of Biff. Griff's bionic implants are fried, and Mad Dog is, well, a crazy mad outlaw.
And Biff's grandma sounds pretty freakin nuts too.
But this is all about the OB. The original Biff. And he was one murderous son of a bitch, as Marty called him about 20 times in #2.\
Let's start with 1955 Biff BTTF #1.
After Marty borrows that little dude's crate scooter and makes the world's first skateboard, Biff and his goons chase him around the square a bit in their car. "I'm gonna ram him!" and "SH############T!" are the last words they say before they get a horse crap bath.
But the dude was gonna ram him! As in, squish him dead! Psycho!
1955 Biff, after getting his car fixed ($300!!!!), ends up chasing Marty down the tunnel again in BTTF #2, and was very intent on running his butt over again! Attempted murder number 5 is in the books. What happened to attempts number 3, 4 and 5? Biff had multiple chances to run Marty into the side of the tunnel, knock him off the car, etc. during the chase. I was nice and gave him only 3 attempted murder charges.
I would move onto the money-hungry, crazy 1985-2015 alternate Biff, but he probably let fame and fortune...
go to his head.