Spiky Boyz is a special term used by Ork from Warhammer, it is a nickname for Chaos Space Marine. This word is invented due to the spiky look of Chaos army's weapons and armors.
Some of the ork slangs: WAGHHH, Dakka, Shoota
Shoota Boy 1: "SPIKY BOYZ ARE COMIN'! WAGHHH!"
Warboss: "Fo Shizzle My Grethins!"