Xander - Xandy, Xander Panda, Xan Xan.
Loony BoB - BoB, Daniel, (SPOILER)BooB.
Citizen Bleys - Bleys, City Bleyz.
Roogle - Roo.
Dr Unne - Unne, Unnesie, Brian.
ShlupQuack - Shlup, Mandee, Crap Face.
Joel - Numa Numa Joel.
Psychotic - Psy.

That's all I can think of right now.