Bowser Jr.'s Fearsome Fleet

Bowser Jr.'s Fearsome Fleet is the last galaxy of World 3 in Super Mario Galaxy 2. Mario is seen fighting Megahammer, a new boss in the game operated by Bowser Jr. in a stage. Hammer Bros. can be found in the pre-boss area. Also, Yoshi can be found in this galaxy as well, considering that he is needed to defeat the mechanical giant. Nothing else is known about this galaxy so far.