A Riddle for You!

What's pink and white, has little tiny wheels, you can put something in, and it goes on our backs?? Any guesses?? Me neither!! when you figure it out can you tell me! That was the description Cole gave me for a toy that i tried desperately to find last night. He was so certain on his description and i just don't know what he was talking about. He kept asking Mommy can you help me find it and i tried so hard! It was breaking my heart. He was getting kind of upset as well. After a couple of hours he forgot about it. Thankfully! With two boys we just don't have much pink in our house. Except my stuff. I'm wondering if it was a toy at daycare and he just got confused or what. He said we got it at the store. I just don't know! We have more toys than most daycares i think and we went through just about all of them.