Johnny Grimes was the killer in the movie "Room 13" He was played by Taylor Goligoski.
There is a horror movie from 1977 about a killer alligator called 'Eaten Alive' And there is a 2007 Australian movie about a killer crocodile called 'Black Water'.
The movie is called 'The Leprechaun'.
The 1988 release of the movie 'Pulse'.
Scream
Very doubtful.
I believe the movie you are thinking of is Scream.
There are lots of movies, but one of them is Disturbia.
Sleepaway camp
In the attic
Blood, dead people, weapons, and a killer.
The Collector.
Silent Night, Deadly Night