Bolas

Make the gesture towards a creature and set of stones bound together by wire spin towards your target. 

Roll a ranged spell attack on a hit the creature take three bludgeoning damage and is restrained. At the end of the targets turn they can make a Strength saving throw against the casters spell attack, and may repeat the attempt at the end of each turn. A critical failure on a save results in -2 penalty to their next attempt.

When the spell ends, the holes loosen naturally.