Blueberry Cake has an aqua color for her fur, a blue frizzy mane (much like filly Pinkie Pie's) and green eyes. Blueberry Cake was seen with a cake costume when she appeared in The Cutie Mark Chronicles. Blueberry Cake's cutie mark is covered by her costume, or it could also mean that Blueberry Cake doesn't have one. Blueberry Cake shares the same design with filly Pinkie Pie, although the colors are different. Blueberry Cake's name was given to her because of her costume she was wearing and the mass amounts of blue on her body resembles a blueberry, thus giving her name; Blueberry Cake.
Blueberry Cake appeared in The Cutie Mark Chronicles when she is seen in Rarity's flashback along with other fillies in a school play when Rarity was designing costumes. In this episode, she was seen wearing a big cake costume. Blueberry Cake has only appeared once throughout the whole My Little Pony: Friendship is Magic series, making her first appearance her last.