Favorite Boss?

So the bosses in Planet Robobot, with the exception of the world 2 boss being just a retread of previous bosses, are perhaps the best in the entire Kirby series. Being that Kirby tends to have some pretty epic boss battles, that's pretty fantastic. Which one is your favorite?

I just have to go with the final boss, which kind of seems like a cop out from the question, but it's one of the best final bosses in any video game I've ever played. It goes on for a VERY long time which could be bad on the go, but I loved how it was so lengthy and epic, and the ending is just insane.

I'd have to go with the final boss, it has multiple phases all throwing out various attacks and having unique ways of dealing with them. Plus it's a shoot-em-up.

I liked the final boss and the fight against Susie since they felt really different unlike the other fights.