Koi Toy is a regular character in the game, Swimmy Sea, that was released on Version 1.0.
Koi Toy looks like a big white fish. It has three pink spots on his body although all his fins stay white. It also has two brown sticks on his mouth and a golden key that is entered in a hole, above his head.
- Although Koi Toy seems a reference to the Koi Toy Lights Up, it is apparently totally not a reference based on the developer's comments.