View source for Way of the Host (5e Monastic Tradition)

=== Symbiotic Skin ===

At third level, you acquire and bond to your symbiote, a small shapeshifting creature that will tend to hide somewhere on your person when dormant. Your initial psychic bond is weak, and the symbiote communicates it's mood and needs very basically. Under normal conditions, the symbiote can survive off scraps from your meals, but if you refrain from feeding it, it will siphon 1d4 health from you at dusk each day.

Also at third level, your symbiote can spread itself to completely cover your body, clothing and carried objects will be encapsulated as well unless you direct otherwise, but the symbiote will part its' surface whenever you require it. While bonded, your Dex and Wis modifiers are treated as one higher when determining your AC, this bonus increases to 2 at 12th level, and 3 at 18th level. Additionally, as a bonus action you can command the symbiote to alter it's surface over your fists, allowing your unarmed strikes to deal either bludgeoning, slashing, or piercing damage as you specify.