Due to your body being in a constant flux of decay, you are resistant to poison and necrotic damage, and have advantage on saving throws against being poisoned.

Additionally, due to your half-dead nature, you do not regain hit points in the same manner as the other races.  When regaining hit points from magical healing (including healing potions), you only receive half the amount of hit points. This reduction does not apply to temporary hit points.

You can speak, read, and write Common, and another language you knew in life.

Through your constant duel with life and death, you've toughened up. Your Constitution score increases by 2.

Despite your half-dead state, and how you may appear to outsiders, you are still alive. You count as humanoid and as alive for the purposes of catagorization through spells and similar abilities.

Before getting cursed, whether through a botched ressurection or ancient curse, you were a human. Your size is medium.

Despite seemingly eerily shambling around, you can still keep up with other medium humanoids. You have a walking speed of 30 ft.

You can see in dim light within 30 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.

Your grim exterior makes it easier to frighten people. You gain advantage on intimidation checks that rely on your physical appearance.

If you go unconscious, becoming stabilized helps you resist death.  If you are stabilized for 5 rounds (30 seconds), you return to consciousness with 1 + your level + your Constitution modifier hit points. Once you’ve used this ability, you can’t use it again until you’ve completed a long rest.