At some point Waldo was born or took up residence in Reptool Ravine, where
he became friends or acquaintances with Ace, Click-Clack, and Revvit.
He is pessimistic and grouchy much to Dozer's amusement. Often critical of all the damage the Dinotrux do to themselves, his idea of fun is categorizing parts by mass. Waldo was initially resistant to change, feeling that Reptools survived best by hiding and were meant to repair or create simple tools, not build things like Dinotrux.