Finding a Windup Inkay in Pokémon Pokopia can be a challenge, especially if you're relying on the game's randomized shop rotations. This particular item is crucial for constructing the "Muddy Playtime" habitat, which also requires floating logs, muddy water, and a towel rack.
Fortunately, a guaranteed Windup Inkay can be found in the Bubbly Basin area, though its location may be easy to miss. The item is situated within a cave deep beneath the ocean's surface.
To find it, depart from the town in Bubbly Basin and head north. You will notice buildings on your right. Below you, a road descends into the deep ocean. Drop into the water and follow this road westward until you reach a pavilion, which is where you obtain the seashell seat for Barboach. Continue along the road past the pavilion and make a left turn when you observe brick blocks on the wall. Enter the tunnel.
Approximately halfway through the tunnel, you will encounter breakable rocks that can be cleared using the Rock Smash ability. Beyond these rocks lies another room containing several grubby pearls, useful for stocking up on in-game currency. The Windup Inkay itself is located in the chamber directly behind the broken rocks, presented inside a red Poké Ball.
While players can also acquire a Windup Inkay by appraising large lost sunken relics or through random item sales by specialty Pokémon traders, this direct method bypasses the need for random chance and ensures you obtain the item immediately.
For players exploring Bubbly Basin further, additional guides are available, including how to locate portal pods for universal storage and how to obtain the Starmie doll to unlock a new Dream Island. Information on the Pokopia cooking recipe list and a Bubbly Basin habitat dex are also accessible.