Vampiric Mosquito

You create a buzzing mosquito, formed of your blood. At the end of each of your turns for the duration, it bites a random hostile creature within 30 feet of you, dealing 1d4 necrotic damage. When the spell ends, the blood mosquito returns to you and gives you the stolen blood. You regain 1 hit point for each time the mosquito did damage, up to a maximum of 10 hit points. You can end the spell early as an action.