Your base walking speed is 35 feet.

You do not need to eat sleep or breathe and gain the effects of a long rest after four hours of light activity

You cannot be put to sleep by any means.

You are immune to poison and disease as well as resistant to necrotic damage

Whenever you are healed you may roll an extra d6 and add it to the value.

Also you gain the ability to reattach and regenerate lost body parts and can even survive without a head.

due to your undead nature your body falls apart easily. whenever you take damage greater than half your current hp roll a d20 and if the number was less than 10 consult the following tables.

if the damage was slashing piercing or bludgeoning.

1 Your body is cut in half horizontally. your lower half retains its movement speed but cannot attack. your upper half has a movement speed of 20 and can attack as normal. this effect lasts until you reattach the halves together and receive healing or take a long rest.

2 Your head is cut off. your body can still move and attack as normal but is blind, unaffected by psychic or mind based abilities and cannot cast spells. your head cannot move on it's own and automatically fails strength or dex saves unless another creature is carrying it and that creature succeeds the save. due to the complexity, you can only reattach your head during a long rest.

3 your leg is cut off your speed on foot is halved, and you must use a crutch or cane to move. You fall prone after using the Dash action. You have disadvantage on Dexterity checks made to balance. you may reattach your or another creatures leg during a short rest or regrow it over a long rest. (If you have the spider legs mutation you just lose an arm instead)

4 your arm is cut off  You can no longer hold anything with two hands, and you can hold only a single object at a time. you may reattach your or another creatures arm during a short rest or regrow it over a long rest

5  lose an eye You have disadvantage on Wisdom (Perception) checks that rely on sight and on ranged attack rolls. Magic such as the regenerate spell can restore the lost eye. If you have no eyes left after sustaining this injury, you're blinded. you can regenerate your eye during a long rest or insert a new eye as an action. (Yes you can take other peoples eyes :D)

6 Major Internal Injury. Whenever you attempt an action in combat, you must make a DC 15 Constitution saving throw. On a failed save, you lose your action and can't use reactions until the start of your next turn. Magical healing of 6th level or higher, such as heal and regenerate, heals the internal injury; alternately, during any kind of rest it heals on its own.

7 Lucky number 7. reroll the d20.

8 Minor Internal Injury. This has the same effect as Major Internal Injury above, except that the save DC is 10.

9 one of your fingers is cut off. you can reattach it  or another creatures finger as a bonus action or regrow it on a short rest

if the damage was elemental.

1 your head is destroyed. your body can still move and attack as normal but is blind, unaffected by psychic or mind based abilities, has blindsight up to 60 feet and cannot cast spells with verbal components.

2 Your entire lower body is destroyed. your head cannot move on it's own and automatically fails strength or dex saves unless another creature is carrying it and that creature succeeds the save. during a long rest you may have another creature help you attach your head to a headless body or you may attempt to to regenerate your body over 1d20 hours..

3 your leg is destroyed your speed on foot is halved, and you must use a crutch or cane to move. You fall prone after using the Dash action. You have disadvantage on Dexterity checks made to balance. you may attach another creatures leg during a short rest or regrow it over a long rest. (If you have the spider legs mutation you just lose an arm instead)

4 your arm is destroyed.  You can no longer hold anything with two hands, and you can hold only a single object at a time. you may attach another creatures arm during a short rest or regrow it over a long rest

5  lose an eye You have disadvantage on Wisdom (Perception) checks that rely on sight and on ranged attack rolls. Magic such as the regenerate spell can restore the lost eye. If you have no eyes left after sustaining this injury, you're blinded. you can regenerate your eye during a long rest or insert a new eye as an action. (Yes you can take other peoples eyes :D)

6 Major Internal Injury. Whenever you attempt an action in combat, you must make a DC 15 Constitution saving throw. On a failed save, you lose your action and can't use reactions until the start of your next turn. Magical healing of 6th level or higher, such as heal and regenerate, heals the internal injury; alternately, during any kind of rest it heals on its own.

7 Lucky number 7. reroll the d20.

8 Minor Internal Injury. This has the same effect as Major Internal Injury above, except that the save DC is 10.

9 one of your fingers is destroyed. you can attach another creatures finger as a bonus action or regrow it on a short rest

Whenever you are dropped to zero hp you may roll a constitution save with a dc of 5 + the damage taken. on a success you drop to 1 hp. you are considered proficient with this save.

this ability does not activate if the damage was radiant or a critical hit

Upon successfully biting a creature you may use this ability to deal a number of d6 equal tp your proficiency necrotic damage. you regain hp equal to the damage dealt by your bite + drain attack.

You can use this ability a number of times equal to your con modifier per long rest

When you determine your ability scores, increase one of those scores by 2, and increase a different one by 1. These increases can’t raise a score above 20. You follow this rule regardless of the method you use to determine the scores, such as rolling or point buy. If you are replacing your race with a lineage, replace any Ability Score Increases you previously had with these.

Your character can speak, read, and write Common and one other language that you and your DM agree is appropriate for the character. The Player’s Handbook offers a list of widespread languages to choose from. The DM is free to add or remove languages from that list for a particular campaign. If you are replacing your race with a lineage, you retain any languages you had and gain no new languages.

Every creature in D&D, including every player character, has a special tag in the rules that identifies the type of creature they are. Most player characters are of the Humanoid type. A race option presented here tells you what your character’s creature type is.

Your creature type is both Humanoid and Undead.

If an effect works on at least one of a creature’s types, that effect can work on that creature. For example, if you are both a Humanoid and an Undead, cure wounds works on you, since the spell works on a Humanoid.

Your size is Medium or Small (choose when you gain this lineage).

You can see in dim light and in darkness within 120 feet of you and can see through magical darkness.

You have a climbing speed equal to your walking speed. In addition, at 3rd level, you can move up, down, and across vertical surfaces and upside down along ceilings, while leaving your hands free.

You have disadvantage on ability checks and attack rolls while in direct sunlight (Although this probably could be solved by wearing a hood or sunglasses)

Your fanged bite is a natural weapon, which counts as a simple melee weapon with which you are proficient. You add your Constitution modifier to the attack and damage rolls when you attack with your bite. Your bite deals 1d6 piercing damage on a hit. While you are missing half or more of your hit points, you have advantage on attack rolls you make with this bite.

When you use your bite and hit a creature that isn’t a Construct or an Undead, you can empower yourself in one of the following ways of your choice:

• regain hit points equal to the damage dealt by the bite
• gain a bonus to the next ability check or attack roll you make; the bonus equals the damage dealt by the bite

You can empower yourself with your bite a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.