Cool Toy is a robot that has changed form, but retains the basic attack system since his first appearance. First, he was a bean-shaped robot suspended on a single wheeled leg. He also had two arms and a bandanna. On his back was a large winder, which partially gave him his name. Occasionally, he looks like a slot machine with two stubby feet. he still retains the winder and bandanna, however.
Cool Toy is presumably one of the many toys Amber owns. In most video games, he is summoned by his Winder. He has very poor stats, with all of them near the worst. However, his attacks are still about as powerful as others, due to their increased base power.
Cool Toy is a slot machine attacker, similar to a few other types of attacks (like Setzer's slot attack from Final Fantasy VI). Because of this, he uses attacks randomly. He may use an unnecessary healing move, or an attack that the enemy absorbs at about the same chance of an attack that causes status errors or neutral damage.