You probably don't know this, but Dwarves and Undead hate one another. I believe the Dwarves hate the Undead because they're abominations unto all that is good, and their very existence is a blasphemy unto the Titans and the most unholy terror.

The Undead, for their part, hate the Dwarves because they're short.

So you might find it a bit surprising that I switched from playing my Dwarf priest to an Undead priest. This change was forced upon me by Bats and Quix, who I wanted to play with, but refused to play anything except Undead. I was fine with this, as I hadn't seen any of the Horde forces yet, so they seemed as good as any.