Dr. Boovian left Boov society of his own accord. Once one of the smartest Booves, his head deflated in an accident, which also resulted in a form of... mental instability. He acts similar to all the other Booves, but when his mental issues start to arise he tends to... really like experiments, which is VERY unboovelike.... And sing. And sing while he's doing horrible things to them just to see what would happen. At first he was mostly avoided, but after his experiments started to become... dangerous in nature and he couldn't find any test subjects he left. He is specifically an easter green in color, though often turns to the deep green when he proclaims 'This will not be ouchpains, you have nothing to fear!'
He has no problem being a loner and is very good at fleeing, in that he still has his Boovness. He does run into Blast and Jam several times though. Sometimes in ways helpful to them, in other ways.... more to his own benefit. Still being extremely intelligent, he has managed without great problem to thrive on his own, in a way more superior to most Booves.
He's green because while he may seem like he takes everything serious what he says, when he tells you there is going to be no ouch pain... yeah he's lying, and it's pretty much become infused into him now. It works to his advantage because while he does change color for some other emotions, lying, he does not. Good luck trying to tell if he is or not.