Waldomar's Crawling Claw

With one sweeping motion, you sever your hand, which drops to the ground and animates as a crawling claw. The wound on your wrist closes instantly.

The crawling claw acts independently of you, but it obeys your commands. It can receive commands telepathically over any distance, so long as its on the same plane of existence as you. In combat, it rolls its own initiative and acts on its own turn. The claw can attack and take other actions as normal, as well as manipulating objects, such as opening doors, turning locks, and fetching items. The crawling claw can activate magic items, but if they require attunement in order to be used, you must be attuned to them. If the crawling claw is holding an item, it can still walk, but it loses its climbing speed. The claw's hit points are equal to 10 plus your Wizard level. The stats of the hand are the same as the caster's and it has a walking and climb speed of 20ft.

Additionally, when you cast a spell with a range of touch, the crawling claw can deliver the spell as if it had cast the spell. The claw must use its reaction to deliver the spell when you cast it. If the spell requires an attack roll, you use your attack modifier for the roll. 

The claw lasts until it is placed next to your wrist, where it can be reattached as a bonus action, leaving only a faint scar. If the claw drops to 0 hit points, it becomes inanimate and can take no actions, except to be reattached to your wrist.