The Lion King 1½ (2004)

Director: Bradley Raymond
Timon and Pumbaa start to watch the original Lion King movie, but Timon keeps insisting to fast forward to when they come in, because they weren't seen in the beginning of the story or anywhere until halfway through. Pumbaa suggests telling the audience their story, which begins before Simba's journey begins. Through this, we meet Timon's mother and Uncle Max, discover why he left his meerkat colony, where he learned Hakuna Matata, how he meets Pumbaa, and the perils they encountered while searching for their dream home.
IMDb