Jihadi White. Basically anybody that came out of Georgetown or UMD. Roy Hibbert continues the tradition. Steve Francis was a Terp as well and a big loser bum most of the 2000s.
Some that come to mind: Darko Milicic, Kwame Brown, Hasheem Thabeet, Joe Alexander, Michael Sweetney, Robert Swift, Shelden Williams, and Jay Williams. Wesley Johnson, Jimmer Fredette, Flynn, Jan Vesley (hot girlfriend though), and Yi Juilian are some more recent bums that just didn't live up to their expectations. Williams is a bit of an asterisk for obvious reasons. Perhaps "bum" or "bust" aren't really accurate, but a sad story for what looked like a very promising player.
Kwame Brown. But I guess it depends your definition of "bum." Then my all-timer. Nikoloz Tskitishvili. I met him, super nice guy, but dang, he couldn't shoot or do anything for anybody.
Royce White Gilbert Arenas Joey Dorsey Derick Fisher Javale McGee Big baby Davis Ty Lawson Stromile Swift
Couple of ex rockets who never managed to stay in the league .... Kirk Snyder Von wafer James "flight" white Joey Dorsey I remember a lot of people wanted Morris almond over Aaron brooks