The scorpion is a pet owned by the Junky Scorpion owner, who wears it on a lace around his neck.
The owner pretended to put the scorpion inside an Air Muscle shoe as part of a test for Katsuya Jonouchi. If Jonouchi was brave enough to put his foot inside the shoe, he would be allowed to buy them. After Jonouchi put his foot inside, the owner revealed that he hadn't really put the scorpion inside, saying he wouldn't want to damage the shoes.
Dark Yugi returned to the Junky Scorpion after finding that the owner had stolen back the shoes he sold to Jonouchi. As the owner handed them back, he tried to sneak the scorpion into one of shoes in an attempt to poison Yugi. However, Yugi saw what he was doing and put a handful of coins inside the shoe. He challenged the owner to a game, where they must take turns pulling coins from the shoe. The winner would be the player who gets the most coins. Yugi even agreed to give the owner ¥10,000 for each coin he got, if he won. The owner became greedy and stabbed the shoe with a knife, trying to kill the scorpion. He then tried to take a fistful of coins. However, he missed the scorpion, and his hand got stuck while holding the coins. The scorpion stung him badly, such that he had to be rushed to the hospital.