Gertie "Xath" Barden...

[Olaf the Stout]

Very well known, as a matter of fact.

Incidentally, its generally understood that the phrase means "hung like an American horse," instead of the smaller peniied Austrailian horse.

I think you'll find that sits under the "Urban Myth" category!

Olaf the Stout

 

[Heckler]

To be fair, I understand the Aussie horses are stouter.