Yoshi's New Island (3DS) Final Boss in world 6-8 Baby Bowser's Castle Break-In. Giant Bowser, King Bowser and Ending. This video shows all Final Boss Battles (No Damage) and Ending in Yoshi's New Island for the Nintendo 3DS. Playlist for all of my Yoshi's New Island gameplay videos can be found below. Yoshi's New Island 100% Walkthrough Playlist:.