Blizzard teases new mount

It's a cat. It's very purple. It kind of gives me a Netherstorm vibe. Blizzard just teased this new mount on the official @Warcraft Twitter account without much of a hint.

My initial thought was it would be another store mount, but now I think another possibility is a Heroes of the Storm promotional mount. Remember the Hearthsteed mount from Hearthstone? Same thing, except for Heroes. That's my guess anyway. Would you shell out $25 for this if it turns out to be a store mount? I think it looks pretty slick.