Barkskin

Level 2 Transmutation (Druid, Ranger)
Casting Time: Template:Bonus Action
Range: Template:Touch
Components: , S, M (a handful of bark)
Duration: Template:1 hour

You touch a willing creature. Until the spell ends, the target's skin assumes a bark-like appearance, and the target has an Armor Class of 17 if its AC is lower than that.