Just a small illustration to my headcanon regarding Wheely…
 
Wheely Bopper was a strange pony with wheels who used to appear in Rainbow Dash’s dreams frequently during her childhood. Together they had all kinds of fun and adventures. Being a product of Rainbow’s imagination the wheeled mare strongly resembled her. As Rainbow grew older Wheely appeared less and less, until eventually she vanished from her dreams completely. Many years later Rainbow still remembers the character fondly. She commissioned Rarity a plushie of Wheely and still hopes that some day she will see her once again.