Where is the 5th Dolphin figure for the mini-game on Tropical Island?

In the hut with the colored faucets, below the red mat on the right side, click the stone between two orange details.

For those still looking for the 5th Dolphin which was not described in the walkthrough --- You can find it in the "red" hanging lantern inside the island sanctuary in the middle of the lake.

I found it in the room with the colored faucets. It's to the left of the mat and pillow on the right side of the screen. It is in one of the details in the step that surrounds the room. Hit the one protruding, it will fall off and you can grab the dolphin.

Also you can use hints if it's the last object you're looking for and you already beat the level