Corkbutt

Undeniably true
What's happened to you
Made from the bark of a tree
Now it's attached to your butt
Instead of your knee
Instead of plastic surgery
Advances in medical science
Make it possible to be
Corkbutt, Corkbutt
Cosmetically corrupt
Gluteal implants
Make your body light
Attached under the 
muscle real tight
New and impressive
Physiological design
Made from pure cork
Strapped to your behind