Even in retirement, Chimp the robot’s still got it. The giant red humanoid crouches down like a Transformer to roll on all fours, then stands up and slowly approaches a door. It sees its world by coating it in lasers, allowing Chimp to reach for the handle, delicately turn it, and roll through the entry.

Two and a half years after Chimp competed in the Darpa Robotics Challenge, it remains one of the weirdest humanoid robots on Earth. But that weirdness is Chimp’s strength. It’s a glimpse into a future that’s teeming with machines you’d never expect. And really, to a large degree those machines have already begun to arrive.

Chimp was born at the National Robotics Engineering Center at Carnegie Mellon, the product of just 13 months’ work by a team of 30 humans. They pieced it together specifically for the Robotics Challenge which … challenged roboticists to construct humanoids that could tackle a disaster situation. They'd have to navigate an environment built for humans, turning valves and climbing ladders and even driving a cart.

But Chimp didn’t look like its peers—hulking machines that walked, usually poorly, like humans. “We didn't really feel that walking was strictly necessary,” says Mike Vandeweghe, lead robotics engineer at CMU. “So we sought to design something that would be more stable over rough terrain." Specifically, something that could roll around, then stand up to free its upper limbs to manipulate objects.

Such are the liberties of biomimicry. You’re more than welcome to replicate how a human looks and moves as closely as possible. But maybe that’s not the best way to go about things. Balancing on two legs is both technically difficult and energy intensive. So Chimp just avoids the problem entirely, transforming itself into a quadruped to roll around on super-stable tank treads.

Which is not to say that a robot walking on two legs won’t have a place in this world. For instance, Boston Dynamics’ Atlas humanoid—which was also developed for the Darpa Challenge—has literally grown in leaps and bounds over the last two and a half years. It can now jump from box to box, then do a backflip off a ledge. Not that that would do it any good in a rescue situation, necessarily. But dexterous bipeds will certainly serve some purpose.

And really, they’re closer than you might think. A bipedal robot called Cassie is for the time being just a pair of legs, but its creators hope the robot will be a workhorse that schleps goods where wheeled robots can’t. Up stairs and across uneven terrain, for instance.