Infernal Cranium is a set cap in Diablo II. It is one of the three pieces of the Infernal Tools item set. Early in the game, the Infernal Cranium can have use for any class. The resistance bonus is handy for a level 5 item, and the damage to mana attribute can help with early mana demands by restoring some mana when damage is taken. As it is a Treasure Class 3 item, it may only be found in Normal Act I. Its high uqlvl make it a very rare drop.