Sumo Slammers is a franchise on Earth that have shoes, video games, card games, and mp3 players.
There are three known colors in the Sumo Slammer cards.
the most common card
the middle card, its the second most rare and the second most common
The rarest of all sumo slammer cards. Ben was trying really hard to get this in the episode Washington B.C. however he still cant get the gold sumo slammer card.