The Koas (both singular and plural) were a sentient species resembling spiders with tentacles on their head native to the planet Koa. They had shrunk their world and placed it in a pyramid to escape their home system and travel to Federation space. The planet's original size was restored in the Mu Arae system with the help of the USS da Vinci. (SCE eBook: Small World) They joined the Federation in 2380. Caliph Sicarios became their first councilor. (ST novel: Articles of the Federation)