Kung Fu Panda: Legends of Awesomeness S01E22 - Has-Been Hero

Po discovers that his favorite wrestler named Kwan is coming to the Valley of Peace, and he is invited to meet his hero in person. Kwan looks weak and feeble as an elderly old ram, and he tells Po that this would be his last fight. Po helps Kwan become strong again, but is tricked. It turns out that Kwan was plotting revenge because of an incident with Po's dumpling (which Po doesn't know about) when he was a panda cub.

Note: This episode was seen on the DVD / Blu-ray for Kung Fu Panda 2, which was released on December 13, 2011.