You'll never guess where to learn Waterfall in Pokémon Pokopia (actually, you will)

Learning Waterfall in Pokémon Pokopia occurs in one of most obvious places you could think of: at the bottom of a waterfall.

What is Waterfall?

As in the main Pokémon series, Waterfall is an ability that Ditto can learn in Pokémon Pokopia that allows them to go up a waterfall while using Surf to swim around. Unlike Rock Punch of Water Gun, this is a movement ability, so it's context sensitive to already Surfing as a Lapras Ditto, and being at the bottom of a waterfall.

Where is Gyarados in Pokémon Pokopia?

Gyarados is in the fourth and final region that you explore in the Pokopia single player story: Sparkling Skylands. This region has multiple islands, and it's only through flying around with Glide that you might stumble upon where Gyarados is. And while I've already said that they're at the bottom of a waterfall… there's quite a few big waterfalls here!

Once you've reached the central island of the Sparkling Skylands, you need to find a water fountain in one of the four corners and look out to the other nearby islands.

Just chat to Gyarados and he'll be more than happy to teach you Waterfall. That's nice, because otherwise you'd be trapped down here for the rest of your purple blobby life! Use Waterfall to ride all the way back up to the top of the island and back to the rest of the missions.