Hippopotas was summoned by Hoopa because neither the heroes, Baraz or Meray had a ground-type Pokémon to help restore the Prison Bottle. When they arrived at Dahara Tower, Bonnie befriended Hippopotas on the way. When Meray gave the sign to use the Pokémon, Bonnie ordered Hippopotas to use Sand Attack. After the evil Hoopa Unbound was sealed away, Hoopa returned Hippopotas to its home and Bonnie thanked Hippopotas for helping them.
|Sand Attack||ground||MS018: Pokémon The Movie - Hoopa and the Clash of Ages|