Vengefull Serpents

Holding a forked tongue of a poisonous snake, you summon 4 spectral serpents that coil arround you and attack opponents. you can designate any number of creatures you can see that are not affected. 

Whenever a creature not designated comes within 5 feet of you, one of the poisonous snakes strikes the creature, make a Melee Spell attack against the creature, on a hit, the serpent deals 1D10 poison damage and disappears.

During you turn, as a bonus action, you can have one of the snakes attack with the same effect.

when casting this spell at a higher spell level, increase the number of summoned serpents by one for each level above 2nd.