Eberron has the mummy lord Malevanor, but he's probably not what you're looking for. Malevanor is a high priest of the Seekers of the Divinity Within, aka the Blood of Vol, and is a well known citizen of Karrnath. He preforms church services, helps direct his faith, and gets quoted in the newspapers.
So not exactly your typical undead, and more likely to lecture the PCs for their indiscriminate use of magic items that summoned him than he is to attack, but you did ask for a wide survey.
Actually it would be a fantastic adventure seed. The adventurers use the (rather silly) bag of beans and ends up summoning the Pyramid of Malevanor while he was performing service for the faithful of the Blood of Vol. Now, he asks the PC to GET HIM BACK RIGHT NOW WITH ALL HIS INNOCENT DISCIPLES. None of them is high level enough to planeshift back.