Homebrew zomboid Species Details

Risen from the grave with little or no memory of their past lives, the Risen wander the world in search of identity and meaning. Their bodies are pale echoes of what they once were—skin stretched thin, eyes sunken, movements stiff and unsettling—but within them stirs a spark of will that sets them apart from the mindless hordes.

Unlike their monstrous counterparts, the Risen are not bound to necromantic masters or cursed with an endless hunger for flesh. Instead, they carry fragments of their former selves—flashes of memory, ghostly emotions, or instincts long buried. For some, this is a blessing, allowing them to reclaim shreds of their humanity. For others, it is a torment, a reminder of a life that can never truly be theirs again.

Despite their unnatural state, Risen retain free will and the ability to make choices. Many become wanderers, adventurers, or mercenaries, searching for purpose in a world that fears them. Some seek to uncover the mystery of their second life, while others embrace their undead nature as freedom from mortal needs such as food, sleep, or breath. Wherever they go, they are met with suspicion, curiosity, or outright hostility—yet those who look past the rotting flesh may find loyal allies, tireless protectors, and souls determined to prove they are more than monsters.

zomboids are usually medium height with most if not all being of the human variety.  

zomboid Traits

undead resilience, grave fortitude, rotting form

undead resilience

The zomboids undead nature makes it so there harder to be put back in the grave from which they risen out from.
When you are reduced to 0 hit points but not killed outright, you can make a Constitution saving throw (DC 5 + damage taken). On a success, you drop to 1 hit point instead.
After your turn has ended you may heal 1d4 worth of damage if your bellow half of your maximum HP and not unconscious. (1d6 at level 10)

Grave fortitude

If hunger is an in game mechanic then the zomboid will need to eat more frequently. They don't need to sleep but will enter a 4 hour trance once per day. They also wont need to breath able to stay underwater indefinitely. 

Rotting form

Your zombie nature makes social interaction harder. You have disadvantage on Charisma (Persuasion) checks against non-undead creatures, but advantage on Intimidation checks.