Off the top of my head... That I know I've used some I came up with some I just read somewhere on here.

Izzy
PongsaShit
RuPaul Williams
JFat
Rafa
Aladdin (Naz)
Tony "PP" Margarito (Plaster of Paris)
Snaggletooth (Hopkins)
Marshmellow Man (Butterbean)
Gollum (Maussa)
Peanut Head (Tarver)
CalzSlappy (Calzaghe)
Powder (Pavlik)
Beaky Buzzard (Darchinyan)
Pernell Shitaker
Sugar Gay Leonard
Cory Stinks