Barkskin

Source: D&D 5.2 SRD Spells

Level 2 Transmutation (Druid, Ranger)

• Casting Time: Bonus Action
• Range: Touch
• Components: V, S, M (a handful of bark)
• Duration: 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.