Arcana Zombie

Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the arcana zombie drops to 1 hit point instead.

Necrotic Absorption. Whenever an Arcane Zombie successfully attacks and consumes a magical user, it gains an additional 10 hit points and temporarily increases its damage output by 5 for the next three rounds.

Mutated Strikes. The attacks of Arcane Zombies deal an additional 1d6 necrotic damage due to the magical mutations caused by the arcane explosion.

Resilient Undeath. Arcane Zombies have advantage on saving throws against spells and other magical effects.

Magical Consumption. If the Arcane Zombie successfully grapples a magical user, it can attempt to consume their magical essence. The target must make a DC 12 Constitution saving throw. On a failure, the target takes 2d6 necrotic damage, and the Arcane Mutant Zombie gains the benefits of Necrotic Absorption.

Adaptive Mutation. Arcane Zombies evolve over time. After consuming three magical users, they gain a random magical ability, such as resistance to a specific element, the ability to cast a minor spell, or a limited form of teleportation.

Dispel Vulnerability. A successful dispel magic cast on an Arcane Zombie weakens its magical mutations, reducing its hit points by 10 and resetting any accumulated benefits from Necrotic Absorption.

Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage (1d6) necrotic damage.