Yu-Gi-Oh! Capsule Monsters is a twelve-episode anime mini-series, serving as a spin-off to the second Yu-Gi-Oh! anime series. The series, animated by Studio Gallop, was commissioned, produced, and edited by 4Kids Entertainment and aired on 4Kids TV in North America between September and November 2006. It is currently the only animated media in the Yu-Gi-Oh! franchise to not see a release in Japan.
Capsule Monsters is set between the Grand Championship and Dawn of the Duel story-arcs of the Yu-Gi-Oh! series, Capsule Monsters involves Yugi, Joey, Téa, Tristan, and Yugi's grandfather Solomon being pulled into a world where Duel Monsters are real. They find monster capsules that they can use to summon monsters. However, in this strange new world, they battle monsters and when their own monsters are attacked, they feel the pain.