Thevrune's Animate Claw

You animate a hand into your service, a crawling claw. Animating the hand used in the casting of this spell, the crawling claw has the statistics of a normal  crawling claw, but you can choose for it to be an aberration, construct, or undead. 

Your Claw acts independently of you, but it always obeys your commands. In combat, it rolls its own initiative and acts on its own turn. An animated claw can't attack, but it can take other actions as normal.

When the animated claw drops to 0 hit points, it falls apart, leaving behind only the hand. It reanimates if you cast this spell on it again.

While your claw is within 100 feet of you, you can communicate with it telepathically. Additionally, as an action, you can sense through your animated claw's senses, and sense what it can until the start of your next turn, gaining the benefits of any special senses that the familiar has. During this time, you are deaf and blind with regard to your own senses.

As an action, if you are missing a hand (of similar proportion to the animated claw), you can attach the claw to your arm, causing it to become inanimate, and take the form of your hand. While the claw is your hand, it no longer counts as a creature or object, and is just another part of your body. You can use your action to detach the claw once more, returning it to the state of your animated claw.

You can't have more than animated claw at a time. If you cast this spell while you already have an animated claw, the spell fails, wasting the material components.

Finally, when you cast a spell with a range of touch, your animated claw can deliver the spell as if it had cast the spell. Your animated claw must be within 100 feet of you, and it 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.