A free Windup Inkay can be found in Pokémon Pokopia’s Bubbly Basin, avoiding reliance on random shop rotations or item rewards. It is important because it is required to create the Muddy Playtime habitat.

The item is inside a cave behind the pavilion where players obtain Barboach’s seashell seat. From Bubbly Basin town, head north, descend into the deep ocean and follow the road west to the pavilion; continue along the road, turn left at the brick blocks, enter the tunnel and break the midpoint rocks with Rock Smash. The Windup Inkay is in a red Poké Ball in the room beyond, while the habitat also needs floating logs, muddy water and a towel rack.