Pokos are the currency used on Olimar's home planet, Hocotate. This was first introduced Pikmin 2 and the plot concerned them. Olimar and Louie had to pay a debt of x10,100 by visiting the Planet of the Pikmin, where collecting Treasures can pay off this supposedly immeasurably large sum of money. In comparison, x100 is more than a year's salary for the average Hocotatian. Pokos are ovular, and thin, and are made of some sort of golden colored material. They bear a strong resemblance to the coins found in the Mario series of video games.
It is unknown how pokos compare to real life currencies.