Feat: Undead Master Dedication
You gain the services of an undead companion that travels with you and obeys your commands. The rules for undead companions appear on page 37 and utilize those for animal companions from the Core Rulebook on page 214. Contrary to the usual rules for companions, as an undead master it's possible for you to have more than one undead companion at a time. However, only one of those companions, your "active companion," follows you during exploration and encounters; the rest are reduced to an "inactive" state that can be easily tucked into an inventory or stored in a nearby crypt. If you ever have more than one undead companion, you gain the Call Companion action, with your undead companions taking the place of animal companions.