Disturber

n.	1.	One who, or that which, disturbs of disquiets; a violator of peace; a troubler. A needless disturber of the peace of God's church and an author of dissension. - Hooker.
	2.	(Law) One who interrupts or incommodes another in the peaceable enjoyment of his right.

Noun

1.

disturber - a troubler who disquiets or interferes with peace and quiet; someone who causes disorder and commotion

bad hat, mischief-maker, trouble maker, troublemaker, troubler