Plated Vesk
Source Player Core pg. 75
Your ancestors were the hardiest specimens of vesk, having traveled far and wide while enduring hostile environments. Your scales count as medium armor in the plate armor group. They grant a +3 item bonus to AC, have a Dex cap of +1, a check penalty of –2, and a Strength threshold of +3, and have the comfort and exposed traits. This item bonus increases to +4 at 5th level. You can wear a flight suit, but you can't wear other armor. You can etch armor runes onto your scales, but you can't install armor upgrades.