look up any word, like half chub:
 
1.
The act of a woman holding cum in her cheeks making them appear puffy like a squirrel's directly after performing an ass-to-mouth. The final step of the brown squirrel is to smack both cheeks simultaneously causing the cum to be sprayed violently from the mouth.
My cum was all over the wall after I pulled a brown squirrel on that chick.
by german skeez January 13, 2009
 
2.
Shoving a furry tail up your ass, but leaving enough hanging out so that while you're munching on nuts you look like a squirrel.
Whoa, do you see Nathan G. over there? He's totally doing the brown squirrel on that guy!
by gower_lover March 31, 2011