bald-headed mouse 

penis

Robs bald-headed mouse is barely visible to the naked eye.

bald-headed mouse by Tedwise October 27, 2003

bald headed mouse on a trampoline 

stretching one's scrotum forward and shaking it up and down so that the tip of the penis bounces on it

hey stuart, did you ever see a bald headed mouse on a trampoline?

bald headed mouse on a trampoline by madfunfrank September 30, 2013