The Grease With The Golden Spring Onion
All his dignity had dissolved when he opened up the package and tremblingly removed an inflatable pig that he proceeded to puff up into its plump, almost perfectly spherical form.
AN APPROPRIATION EXCERCISE #2 (Little Fun)
"is that an inflatable pig?" sedric looked over in the corner of the bedroom and laughed, a mixture of embarrassment and amusement.
Damo's ride (Conclusion)
The shafts suddenly tensed together inside him, and with his last coherent feeling as his eyes filmed, he felt his torso begin to expand as three fountains of fertility filled him like an inflating pig's bladder...
Sir Wolfie gets Taught a lesson....Chapter 2.
The vent bulged near the base of ruth's tail, and a ring of muscle the size of an inflated pig's bladder emerged, rippling as a cloud of gas was released. "now dock me," ruth said.
The Catgirls Quadrilogy, Chapter 3 - Cats and Dogs... and Horses
Now, i don't know how large a bull bladder is, but i do know that in the old days, kids who lived on farms often used inflated pig-bladders for footballs. that should give you some idea of how expandable those things are.