A Commitasaurus Rex is someone who is exceedingly devoted to something which they are passionate about.
Guy 1: "Dud you wanna go to the movie tonight"
Guy 2: "No, I can't, I'm a Commitasaurus Rex to my art."
Guy 2: "No, I can't, I'm a Commitasaurus Rex to my art."
by Durock Durock January 6, 2011