I would argue that this wheel isn't made out of odd matter, it's made out of motors and springs (rubber bands) the same way all actuators are. It behaves in a way that is analogous with odd matter, which the article defines as:

> The odd wheel grew out of Coulais and Vitelli’s past work on the physics of “active matter” — an umbrella term for systems whose constituent parts consume energy from the environment, such as swarms of bacteria, flocks of birds and certain artificial materials. The energy supply engenders rich behavior, but it also leads to instabilities that make active matter difficult to control.

I'm a little confused by the idea of this being spontaneous as well, especially since it's repeatable. Emergent, maybe? On the whole it just seems like a type of open loop locomotion control that doesn't rely on limit cycles. Which is interesting but not "spontaneous".