Become Undead

Any race other than Aasimar or Warforged can acquire this feat. This feat can only be acquired by undergoing a surgery from a necromatic doctor (usually an NPC like a mad scientist or something similar to Dr. Frankenstein). A dead character can use this feat to be raised, but only if the surgery is performed within 7 days of death and if the body is whole or can be pieced back together. Clerics and Paladins can use this feat but it is ill advised because so many of your own spells will work against you. It may also not be a good idea to use this feat if a Cleric or Paladin is in your party.

This feat gives you the following traits:

• You are now undead/humanoid 
• You can now only stomach raw meat as food. Humanoid meat tastes best to you, but meat from other sources is still tasty. Humanoid raw meat regains 2d4+1 HP per pound, any other raw meat is 1d4+1 HP per pound. Creatures of the following types can be used as a source of raw meat: Beast, Fey, Dragon, Fiend, Giant, and Humanoid.
• You can use an action once per short rest to quickly eat 3 pounds of a corpse (or raw meat you are carrying) during combat. Out of combat you can eat as much meat as needed to regain health, as long as enough of it is available. 
• You no longer need to sleep but can do so if you choose.
• Being exposed to direct sunlight for more than 8 hours a day results in 1 level of exhaustion.
• Sleeping does not remove exhaustion. To remove 1 level of exhaustion you must eat half your weight in raw meat.
• Healing spells do not work on you. Healing potions still work as normal.  
• You are nearly immortal. If you reach 0 hit points you immediately stabilize. Negative max hit points will still result in instant death. 
• If you lose a limb, you can replace body parts from dead or undead humanoids. You could technically use this to replace your entire body if decapitated, but will need to replace your strength, dex, and constitution with that of the humanoid body you have now acquired.
• Most undead with low intelligence (such as zombies or skeletons) are not hostile toward you. They see you as one of their own and have no interest in hurting or killing you, even if you attack them first. They will still attack living members of your party. They may attack you if under the control of another being. 
• After being undead for at least 30 days you gain the ability to telepathically communicate with other undead within 30 feet of you. The undead creatures that you wish to speak to must be able to understand a language that you can speak. 
• You are immune to necrotic, and poison damage
• You are resistant to psychic, and cold damage
• You are vulnerable to radiant and fire damage