El Diablo was a one time bull who appeared in Hi Hi Puffy AmiYumi.
El Diablo only appeared in the episode, Ole! When Kaz took on a bull by carrying red food and wearing a red piece of clothing, Ami and Yumi pulled him out of the way, they were crowned the winners of a bull fight and were to challenge the biggest and baddest bull in Mexico, El Diablo. Ami and Yumi tried everything to escape, but failed every time. When it was the day to fight El Diablo, they tried everything they could, like sweet talk and hypnotism. Finally, El Diablo was defeated when Kaz dressed the tour bus as a bull, knocking out El Diablo. Kaz was crowned the best bullfighter in Mexico.