As dictated by the needs of my own campaign.
You have been brought back from the dead. Your consciousness slowly dwindles. Your new class is ZOMBIE. You love and hate the same things you did in full life. You also love brains now. This is immutable.
Your new HP is d12+4. Your HD is a d12.
You are the same level you were in life.
Your class damage is d10/d8.
You can wear any armor and wield any weapon you could in life.
You are harmed by spells that help the living. You can only regain HP by eating brains. 1d12+1/brain. Full HP for eating the brain of your own species.
You begin with a d8 Humanity Usage Die. On a 1-2, it drops a die step (d8>d6>d4>0) and you should roll on the Poor Zombie Impulse Control Table. When your Humanity usage die expires, you lose control of your zombie urges and should consider going out in a blaze of feasting glory before being put down by your fellow adventurers, instead of tepidly hemming and hawing over which of your friends to snack on first. Zombies CAN'T apologize. Also at this point, when you reach 0 HP, you’re dead. No, really dead. Forever.
When to roll your Humanity Usage Die:
-you kill something
-you watch someone eat meat
-you touch flesh to flesh with someone else
-1st blood is drawn in a 1 hour period
-another PC goes Out of Action
When you reach 0 hp, you are Out of Action. Roll on the Zombie Out of Action table.
Poor Zombie Impulse Control Table (roll d6)
1. You feel your hunger rising. Remember something about your humanity. That calms you down.
2. Test your CHA. If you fail you feel compelled to make a testing bite at the nearest living thing (1 attack).
3-4. You must FEAST on the nearest living thing! Test your CHA each round to regain your humanity. Test with Advantage each time you feast on a juicy brain.
5-6. You must FEAST! And you're CONTAGIOUS! Any PC who fails a CON test when bitten by you will return as a zombie WHEN they die. Test your CHA each round to regain your humanity. Test with Advantage each time you feast on a juicy brain.
Zombie Out of Action Table (d6)
1. You are still a live and unharmed. Well... you know what we mean.
3-4. You lost a limb! -3 to STR and DEX
5. Hit to the head. -4 to CHA.
If by some miracle you survive long enough to level up without eating all your friends, roll UNDER your attributes to see if they DECREASE. You are degrading, after all. Roll twice for DEX and CHA.