Mew (M08)

A Mew made a major appearance in the eighth Pokémon movie, Lucario and the Mystery of Mew.

Mew first appeared unknowingly to the viewers, as a Tailow, landing on the castle and transforming into a Treecko. While Ash, May, Brock and Max were getting dressed for the festival, Mew, still as a Treecko appeared to Ash's Pikachu, transforming yet again into a Pichu. Later, while the Pokemon tournament was going on, Mew joined Queen Eileen's Mime Jr. as another Mime Jr. Queen Eileen's maid was surprised to see Mew change from a Mime Jr. to an Aipom. While the ball was going on, Mew, still as an Aipom was shown to be playing with Ash's Pikachu, seeing this, Ash released all his other Pokemon to join the fun, this was followed by May. A bit later Mew showed all the Pokemon an unused attic with many toys. After that, Mew transformed into a Pikachu and started dancing Ash's. When Meowth fell through the window, Mew transformed into it's real form for the first time. When Kid's two Weaviles tried to get Mew, it turned into a Meowth for a short time. When Max peered through the window, Mew transformed to it's real form, seeing the the Meowth scheme had not worked. When teleported it, Meowth and Ash's Pikachu to the top of a tower, it chahged into a Pidgeot and flew them to the Tree of Beginning. Mew then appeared in ocassional cutscenes trying to cheer up Ash's Pikachu with toys, then followed it to look for Ash. Mew nearly sacrificed itself to save Ash, Kid, May, Max, Brock, Jessie and James. Lucario saved it, and the tree, but ended up dying.