I believe that dodge made a 6-wheel drive vehicle for the army that was dubbed a T-Rex. Might this not be the inspiration for the name here?

In any event, it's still cool. The best I had growing up was a "Fast-Trax" and a "Caterpillar". The later being an 18 wheeler with 9 independent axles and 9 sets of suspension with the back 2 sets being powered. Imagine if they moved to the toy industry and applied some sort of "smart-weighting-system" and faster motors. You'd scale a cliff in no time