Dragon-like? ...not sure where you're seeing the resemblance to a dragon but the WL2 version is the one I grew up with first and I think he looks cooler.
I always liked the Bobo in the first game. It's sprite is just so big and it actually looks like a bird. The Bobo in #2 looks kinda creepy and loses the charm that the first one had.
I think the one from 1 looks more impossing! Since he appears as a boss in both games I like to think hes an important part of Syrups crew, so I think the design is more suiting. Must be the eyes that do it for me <:
I can't choose. I like them both, and think that each design suits it's game respectively. The big Bobo looks more menacing which makes sense since you can die in Wario Land 1 whereas in Wario Land 2 the bosses are kind of just small roadblocks that can't kill you and only send you back.