Warlock subclass
Undying
Disease resistance, death avoidance, and slow bodily decay.
Undying starts by changing the normal Warlock play pattern through Expanded Spell List; Among the Dead, giving the subclass its first clear mechanical identity.
Later features such as Defy Death, Undying Nature, Indestructible Life expand that identity at higher levels, so the subclass has a clearer role in combat, exploration, utility, or support.
Expanded Spell List; Among the Dead
1st level
Gain death-defying spell 
D&D Portal - Spells Spellcasting rule Spells is a spellcasting rule used by spells,
class features, and magical effects. Full link: https://dnd-portal.com/rules/spellcasting/spells/ options, learn Spare the Dying, resist disease, and make undead save before attacking you.
Defy Death
6th level
Regain hit points 
D&D Portal - Hit Points Combat rule Hit Points is a combat rule used by attacks,
damage, defenses, or turn order. Full link: https://dnd-portal.com/rules/combat/hit-points/ after succeeding on a death save or stabilizing another creature.
Undying Nature
10th level
Stop needing air, food, drink, or sleep and age far more slowly.
Indestructible Life
14th level
Use a bonus action 
D&D Portal - Bonus Action Action rule Bonus Action is an action economy rule used to
describe what a creature can do on its turn. Full link: https://dnd-portal.com/rules/actions/bonus-action/ to regain hit points D&D Portal - Hit Points Combat rule Hit Points is a combat rule used by attacks,
damage, defenses, or turn order. Full link: https://dnd-portal.com/rules/combat/hit-points/ and reattach severed body parts.
FAQ
What is the Undying subclass?
Undying is a specialised subclass option that builds on the features and progression of its parent class.
Read more: Undying 
D&D Portal - Undying Warlock subclass Disease resistance, death avoidance, and slow bodily decay. Full link: https://dnd-portal.com/classes/warlock/undying/
How does the Undying subclass work?
The Undying subclass changes the character’s play style through its own feature progression.
Read more: Undying D&D Portal - Undying Warlock subclass Disease resistance, death avoidance, and slow bodily decay. Full link: https://dnd-portal.com/classes/warlock/undying/
What features does a Undying get?
The subclass page lists the features gained by a Undying and explains their effects.
Read more: Undying D&D Portal - Undying Warlock subclass Disease resistance, death avoidance, and slow bodily decay. Full link: https://dnd-portal.com/classes/warlock/undying/
Is Undying a good subclass?
Whether Undying is a good choice depends on the role, abilities, and play style you want for the character.
Read more: Undying D&D Portal - Undying Warlock subclass Disease resistance, death avoidance, and slow bodily decay. Full link: https://dnd-portal.com/classes/warlock/undying/
How do you play a Undying?
Use the subclass features to specialise the normal class play pattern and support the role you chose.
Read more: Undying D&D Portal - Undying Warlock subclass Disease resistance, death avoidance, and slow bodily decay. Full link: https://dnd-portal.com/classes/warlock/undying/