Wikipedia
Tazos are round circular disks, which are found in packets of chips made by Frito-Lay and its subsidiaries around the world. The idea behind Tazos started out similar to Pogs, whereby each Tazo contained a score value, and a game was played to 'win' Tazos from other players.
Tazos have been released in several different formats, ranging from the original circular disks, to octagonal disks, and in later years, to resemble more of a collectible card. In addition to the Japanese Pog Battle game, some Tazo series feature small incisions around the outside, allowing players to fit them together and build things. The Star Wars series also included additional pieces which allowed players to construct notable space ships.
Tazos are commonly made from a plastic base, but some series have been produced from cardboard or aluminium (such as the Australian Yu-Gi-Oh! Metallix series).