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

The obsidian idol head is a rare reward from the Squeal of Fortune. They are part of the Grinning idol promotion. Combine with the body and arms and legs to get experience in the Attack, Dungeoneering, Farming, Fishing, and Thieving skills.