Whirligig is a noun that refers to a toy that spins around. 

Our word of the day came from Late Middle English and meant ‘a whipping top.’ Although it originally referred to a specific toy, it later was used to describe any kind of toy that spins. Example:

That whirligig had my son transfixed all day. I’m sure in time, it’ll take much more to capture his attention, but for now, it's fun to see that a simple spinning toy can give him so much joy.