Blastasaurus Rex Share definition Flag Someone who smokes (or "blasts") weed all the time, or someone who has been smoking weed for a long time. Eric used to be such a Blastasaurus Rex, but now he done got himself religion. Blastasaurus Rex by Shit_4_Brains June 23, 2007 0 0 Get merch Get the Blastasaurus Rex mug. Buy Now — $32.95 See more merch