Tala's Vexing Viper

You summon a flaming snake that strikes out at an enemy momentarily binding them. When a creature moves within 10 feet of you, as a reaction can make a ranged spell attack on the target. On a hit the target takes 2d6 fire damage and has it's speed reduced too 0 until the end of it's turn. The snake then curls around you for the duration of the spell.

Until the spell ends, you can use your reaction too recast it as long as the conditions are met.