Forest Troll High Priests are forest trollpriestcreeps that can be encountered in many tilesets - primarily Lordaeron and Village alongside their Fall variants.
The Forest Troll High Priest is a powerful support unit who will gladly offer his services to you for a rather high cost. Apart from higher stats than his initiate, his Heal recovers more health and he also has Inner Fire, making him a versatile support unit.
However, he has fairly low health and armor, so he needs to be handled carefully. He is only available for service in the Cityscape and Dalaran mercenary camps in The Frozen Throne.