Simple: Fuelless, Self Running Motor?

[Ben Framed]

https://www.youtube.com/shorts/texmO83Rptk?feature=share

[BeeMaster2]

Notice he never turns it upside down. Cut into the underside of the bottom board is a power source of some kind.
Jim Altmiller

[Ben Framed]

Maybe so... I noticed a small slit in the mainframe or mask when he turned it around, which could possibly allow for a string being used as a belt? With the motor and battery being hid in the base? Did you notice the base is hollow? The base is a wood covered top with is what looks like pins or small nails holding it down?

[animal]

I'm thinking fake .. batteries in the base, small pancake electric motor embedded in the upright support driving the flywheel-block-thing.
Otherwise, looks like a mock-up of an alpha type Stirling engine ... Then it would need a heat source on the side cylinder and cooling fins on the "syringe" cylinder.
Plastic syringes usually make horrible pneumatic cylinders, btw. They are really sensitive to heat and usually have a wonky bore which is compensated by a thick double-seal rubber piston. Once you get them sealed, it takes a fair amount of pressure to get the piston to move. A few thousandths out doesn't matter when you're pushing a liquid into someone's butt with your thumb but it does when you're pushing the piston with air. They're really cheap, so I've tried all sorts of stuff with 'em... usually, either they just don't move or I blow them up.