Monsters Crash the Pajama Party is an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 horror film

Horror film

Horror films seek to elicit a negative emotional reaction from viewers by playing on the audience's most primal fears. They often feature scenes that startle the viewer through the means of macabre and the supernatural, thus frequently overlapping with the fantasy and science fiction genres...

from 1965.

Synopsis

A group of teenage girls spends the night in an old dark mansion as an initiation into a college sorority. What they don't know is that the building is actually the headquarters for a mad scientist and his hunchbacked assistant, who are experimenting with turning humans into gorillas.

Cast

• Vic McGee as Mad Doctor / Lt. Hudson
• James Reason as Professor Williams
• Clara Nadel as Miss Petrie
• Pauline Hillkurt as Draculina
• Charles Hegen as Igor