Brainnado

It's like a brainstorm but more violent and leaves ideas scattered around and falling from the sky in weird places.

For movement; The character could propel themselves by a violent or sudden means that launches them through the air and they are left to brace for impact and hope they landed somewhere where they wanted to be. Their surroundings could be full of damaged objects that the character has collided with that aren't explained until the character is seen moving for the first time. Some of these objects could be based of props from pinball machines.

Alternatively the means of propulsion could be a powerful spring or spring-based mechanism. Unless the character is organic in which case it could be a coiled tail of similar appendage.

The character would need some kind of protection for their head, like and acorn cap or something. Or natural body armour like an armadillo (if it's organic) or a thick plate/helmet if it's mechanical.

For movement; All these are alternatives for the dandelion idea I had earlier. Each carries a different style of motion but all are influenced by the air, allowing room for conflict in the narrative for lack of control. The sycamore seed would be the most energetic of the movements with its rapid spinning, whereas the others hold a far more peaceful drifting style of motion. If this was to be the character's primary means of motion then they would probably a rather placid or docile character (with the exclusion of the sycamore seed which could produce a slightly confused but energetic character).

For materiality; A character made, or possessing rubbery appendages would probably have a malleable body. This would also influence the nature of their movement as well. The character would probably be able to reach afar to grab things or contort their body to move about.

For materiality; A character with a liquid body that is viscous enough that it can essentially be atable without a container could be interesting. Their motion would be very fluid (let's face it, there is no other way I could describe that) but probably slow and creeping. Perhaps they could be contained within a solid suit or something that protects the liquid creature inside?

For meaning; The character could be lonely and constructing an imaginary friend for themself or looking for one. Their equivalent of a teddy bear. Being a unique, alien character they could find a friend in unconventional objects.