Skull Servant

The skull servant doesn't require air, food, drink, or sleep.

When the skull servant would be reduced to 0 hit points, it can choose to be reduced to 1 hit point instead. It can use this trait a number of times equal to the spell's level.

While the skull servant is within 100 feet of you, you can communicate with it telepathically. Additionally, you can use your action to see through the skull servant's emerald eyes and hear what it hears until the start of your next turn, gaining the benefits of any special senses that it has. During this time, you are deaf and blind in regard to your own senses.

If the spell's level is at least 3, the skull servant is immune to effects that turn undead.

If the spell's level is at least 4, the skull servant has a flying speed^'24 equal to its walking speed. If the spell's level is at least 8, the skull servant can hover.

If the spell's level is at least 6, the skull servant has immunity to bludgeoning, piercing, and slashing damage from nonmagical attacks.

If the spell's level is at least 7, when the skull servant is subjected to an effect that allows it to make a saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw.

If the spell's level is at least 9, the skull servant has truesight to a range of 60 feet.

Melee Weapon Attack: your spell attack modifier, reach 5 ft., one target. Hit: 1 piercing damage plus necrotic damage equal to the spell's level. If the spell's level is at least 5, the target's hit point maximum is reduced by an amount equal to the necrotic damage it took from the attack until it finishes a long rest^'24. A creature dies if its hit point maximum is reduced to 0.

The skull servant collapses into a pile of bones. Until it reconstitutes itself, it is indistinguishable from an inanimate pile of bones, and magic that normally detects the presence of undead fails to detect it. While collapsed, it is prone, its speed is 0 and can't increase, it has disadvantage on Dexterity saving throws, it can't take reactions, and the only action it can take is a bonus action to reconstitute itself.

When you cast a necromancy spell with a casting time of 1 action, you can have the skull servant use its reaction to allow you to cast the spell from its position. The skull servant must be within 100 feet of you. If the spell requires an attack roll, it uses your spell attack modifier. If the spell has a range of Self, the spell treats the skull servant as the caster.