Horro tales patrick originates from a short comic where he killd Plankton for unknown reasons.
Patrick wears Squidward's face as a mask, which is tied with a rope around his face, he wears a pink butchers outfit and wields a bloody knife.
This version of patrick star is pretty aggressive and sadistic, and yes hes obliously still a starfish just a psychopathic one.
It seems to be implied that his cells were altered turning him into this monster.
His known victims are squidward and plankton