For the quest The Sum is Greater than the Parts you take control of Nergeld, the freaky looking guy above, and defend the Hall of Horrors until Dr. Terrible shows up.
In The Art of Being a Water Terror quest you possess a Water Terror and use it to slay 10 vrykul. I think he looks sweet!
In the quest Army of the Damned you have to raise an army of 100 Ghoulish Minions. I should always have 100 minions at my side. No one would dare bother me rolling through town with a ready made army.