Barkskin

2nd-level · Transmutation

Casting Time 1 action

Range Touch

Components V, S, M (A handful of oak bark.)

Duration Up to 1 hour (concentration)

Classes Cleric, Druid, Ranger

You touch a willing creature. Until the spell ends, the target's skin has a rough, bark-like appearance, and the target's AC can't be less than 16, regardless of what kind of armor it is wearing.

Source: 5e Core Rules · OGL/Open