These popped up on the Arena and a couple other places after it was found on Taobao.
Each character comes in a plastic egg and is “buildable.” The manes, tails and wings (and AJ’s hat) can be pegged into them. This lets them fit easier into the pods.
They look like the sort of thing you can find in vending machines at grocery stores. The quality is pretty low, so they shouldn’t cost more than a few quarters.