The BradyGames guidebook has a photo of it as well as a description, so if it's a rumour, then it's gotta be one heck of an orchestrated litany of lies.

I'm pretty sure it's real, just so pointlessly obscure that only someone who really wants to see every ability would attempt to get it.
Plus, there's probably some short cut-scene when you acquire it, like there is with the Mascot dressphere.