This art has been completely redrawn from the original card's artwork and shows the cover of the 2nd book on these fat ponies. The card's info says:
The Legend of Overweight Pegasai
Normal Spell
Select 1 "My Chubbier Pony" or "My Chubbiest Pony" monster you control, then apply the appropriate effect:
- "My Chubbier Pony" monster: Treat it as a Chubbier Pegasus Pony-Type monster and have it gain 500 DEF until the End Phase. - "My Chubbiest Pony" monster: Treat it as a Chubbiest Pegasus Pony-Type monster. It can attack your opponent directly this turn.
Rainbow Rare