When a mare goes into heat, she will shove the biggest thing she can into her holes in order to get a sense of fullness. Where possible a mare will take a male (of any species) and take his penis into her vagina.

While, not recommended it is known for the odd mare to pick a rhinoceros to mate with during this period of time. The reason this is not recommended is because of the size of the Rhinoceros male's penis. Unfortunately this downside is what attracts the mare to the rhinoceros.

The rare creature Pinkius Piecus, can currently be found engaging in this act with George Cluney, the ultimate rhinoceros. This happens every year, Pinkius Piecus offers herself to the rhinoceros king as tribute for the pony tribes in order to halt the invasions.

At this moment the rhinoceros is thrusting his massive rhino penis into her anus, her vagina is currently leaking the remnants of their last copulation.

They have been at this for hours now, Pinkius Piecus throwing her whole body into the tribute so that equestria can be saved.

"You're tribute is acceptable" George Cluney grunts as he cums inside ponyville's anus, his cum spraying out of her mouth so deep is his cock.

Author's Note