I’d say yeah. Not all forms though, I’d say starting from Super Saiyan 1 and on he probably could. Might struggle at first, but eventually he’d do it without batting an eye. But Kakarot wouldn’t do that, he’s a nice guy.
Vegita would probably do it just to piss off Thor though.
I mean I like Vikings and everything, but the DBZ gang pretty much are gods. (and they kill godlike creatures, too, no hammer needed) And come on, if that green bastard from Marvel can steal Mjölnir, so can fuckin Kakarot. As for the hammer not being able to be lifted by unworthy dudes, well I denno, pretty sure Wotan didn’t plan on getting munched by a wolf. Faulty haha. And anyways, Kakarot probably would be worthy.
And yes, this is probably one of the most important things we should all be discussing.