Erika's Leech Seed

You scatter a handful of enchanted grass seeds over another creature, which grows into life-draining vines. The target must succeed on a Dexterity saving throw or take 1d4 necrotic damage, and you regain hit points equal to half the amount of necrotic damage dealt (a minimum of 1). Until the spell ends, you can use your bonus action to deal an additional 1d4 necrotic damage, regaining hit points equal to half the amount dealt (a minimum of 1). The target can use an action to remove the vines, ending the spell.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d4 for each slot level above 2nd.