1.) Friday the 13th (1980)

A real bull snake had his head chopped off during one scene. Even worse it was actually a pet belonging to a local animal handler, who was reportingly devastated after learning what happened.

2.) Cannibal Holocaust (1980)

This film featured the killings of *several* animals, which included a large sea turtle, a muskrat, a pig, a tarantula and two monkeys.

3.) Ben-Hur (1925)

During the filming of the chariot race, the production used tripwires to make horses fall on cue. It is estimated that up to 100 horses were killed or had to be euthanized due to broken legs and broken necks during that single sequence.

4.) Jesse James (1939)

To capture a shot of a horse jumping off a cliff into a river, crew members placed a horse on a greased platform and tilted it, forcing the animal to slide 70 feet to its death.

5.) Heaven’s Gate (1980)

Director Michael Cimino’s production was accused of blowing up a horse with live dynamite, bleeding horses from the neck to use their real blood for "authenticity", staging actual, illegal cockfights and disemboweling cattle to provide "realistic" entrails for battle scenes.

6.) The Adventures of Milo and Otis (1986)

Because it was filmed in Japan without AHA oversight, reports surfaced that over 20 kittens were killed during production. Other scenes include a cat being thrown off a 150-foot cliff into the ocean and a pug being pitted against a live bear.

[Loathed Trope] Animals were indeed harmed during the making of this film