Knifomaniac
A person who is obsessed with knives. This usually comes with violent tendencies.
Dude 1: Hey, u know my friend with all those knives?
Dude 2: Do u mean the knifomaniac?
Dude 3: Yes, that guy.
Dude 2: Do u mean the knifomaniac?
Dude 3: Yes, that guy.