From Wiktionary, the free dictionary
Blend of white (“Caucasian”) + booty (“buttocks”)
whooty (plural whooties)
- (slang) A white girl with large buttocks.
2009 May 26, “Whooty”[1]performed by Edubb:she's a whooty, a white gurl witha booty
2011, Cynthia White, Forever Queen, Pulse Blaze, page 6:Jess was what we referred to as a “whooty”, a white girl with booty.
2012, Nikki Carter, Time to Shine, New York: Dafina Kteen Books, →ISBN, page 89:“You did good, Ms. Whooty,” Big D says. Ms. Whooty is Big D's nickname for Bethany. The white girl with a big booty = whooty.