From Bulbapedia, the community-driven Pokémon encyclopedia.
Pokémon Tazos are small collectible round discs that were found in bags of Frito-Lay chips in the 1990s. While Tazos do not exclusively feature Pokémon, they did adopt the phrase "Gotta Catch 'em All!" as part of their slogan. Pokémon Tazos feature not only Pokémon species, but human characters from the anime as well. Some Tazos, rarer than the others, had holograms.
Latin American versions of front and back of a Wartortle
Tazo and a holographic Misty
Traditionally, Tazos are played in a manner similar to Pogs. Players form equal stacks of face-down Tazos and try to "win" Tazos from the other player by throwing a Tazo at the stack and keeping any Tazos that land face-up after being knocked over.
Pokémon Tazos are also assigned elemental types with strengths and weaknesses printed on the back. Human characters are considered strong against all elemental types.
Pokémon Tazos were available in many countries worldwide, including several Latin American countries, Brazil, and Israel.