Who is this dude?

This quantumania marketing is getting weird

I think it might just be meant to depict a fat little Japanese peasant/laborer. The bandana-style headband tied in the front smacks of some kind of worker like a farmer or a fisherman. I don't know why people keep suggesting it's the Buddha. It's clearly not (too fat, and has none of the defining physical characteristics). Nor is it Budai/Hotei (which is the fat guy a lot of people confuse with Buddha).

It's a neat little inkwell though. Looks like it's meant to be a stand for your pen as well. It reminds me of a lot of the tourist junk my grandpa brought back from Japan in the '50s when he was stationed in Korea during his military service.

Google image search suggests it's supposed to be Budda

spitting image of my mother in law

Any other identifiable markings on it, like on the bottom?

That's definitely baby Krang from TMNT.

Seems like a poorly cast Buddha sculpture to me. Something about the hand gesture.

Google ”Olmec figurine”, there’s definitely a thematic resemblance.