Coral Athamaru
Source Pathfinder Howl of the Wild
Coral covers patches of your body, which provides a natural layer of defense. Coral athamarus often choose Coral Symbiotes and other related ancestry feats. The coral plates are medium armor in the plate armor group that grant a +4 item bonus to AC, a Dex cap of +1, a check penalty of –2, a Speed penalty of –5 feet, a Strength value of +3, and have the aquadynamic and comfort traits. You can never wear other armor or remove the coral. You can etch armor runes onto the coral.