Zombie head
Mission Imp-possible was removed from RuneScape after an update, but still exists in-game for those who had obtained it.
[FAQ] • [doc]

Mission Imp-possible is a joke item available from Balthazar's Bargain Barrel in October 2015 by using a rummage ticket on Balthazar's Bargain Barrel. It currently has no additional dialogue when used on Wizard Mizgog as other joke items from the barrel do when used on the referenced non-player characters of those items.