Headmaster's Charge

Headmaster's Charge is a staff that, when used, gives party members a buff that increases intellect by 20, making this staff highly sought after for PvP and raids. In raids, it is often used by support characters such as priests and druids, who are less likely than DPS casters to have a raiding epic like the Staff of Dominance. The buff stacks with the Arcane Intellect buff from mages; however the staff must remain equipped or the buff will disappear.

Source
This item is a very low drop from Darkmaster Gandling, the final boss of Scholomance.