B5 Guy Share definition Flag A socially awkward fan of the Babylon 5 franchise. Particularly the ones who use the series to escape their lack of grounding in the real world. B5 Guy failed animation class again, because he spent all his time downloading models of Babylon 5. B5 Guy by Mario Rogic January 15, 2003 0 0 Get merch Get the B5 Guy mug. Buy Now — $32.95 See more merch