A rare bird has landed at the University of Michigan. She has no feathers and no head. She stands up on what look like backward-facing knees. The bird starts to propel herself across the ground—on two legs held together by bolts and screws. Say hello to Cassie the walking robot.

Engineers at a company called Agility Robotics built Cassie. She’s a great example of biomimicry—using designs from nature to solve human problems. Her leg design is very similar to the legs of an ostrich-like bird called the cassowary (pronounced CASS-ah-ware-ee). That’s where the crazy knees come from.

Cassie weighs about 66 pounds. She stands a bit over three feet tall. Each of Cassie’s legs has five motors. Her makers hope future versions of the bot will help rescue people stuck in dangerous or hard-to-reach places. What makes Cassie qualified for this? She has lots of energy—even if it does come from a battery. She can walk for four hours before her juice runs out. She could travel into dangerous situations instead of human rescuers. Her ability to walk easily on rough and uneven surfaces makes her perfect for the job too.

At least, she normally walks easily.

Jessy Grizzle is the director of Michigan Robotics. He and some of his students are testing Cassie out. They take her for a stroll on a walkway. At first, things go well. She moves along a grassy, sloped surface. And then she takes a serious tumble and face-plants on the concrete! Cassie flunks the test.

If you were lost in the mountains, would you call this headless, man-made bird for help? That’s an easy “nope”—for now. After her fall, Cassie is lying in a heap on the ground, scratched and a little nicked. But she is built to last. She and her inventors will try, try again.