Shrowser

Shrowser is a combination of Bowser and the spirit of the Elder Princess Shroob. It is the final boss to be encountered in the game Mario & Luigi: Partners in Time; oddly, the boss battle is similar to a mini-game. After Bowser ate the purple mushroom that held the soul of Elder Princess Shroob, he got possessed by her. Mario, Luigi, and their baby forms had to fight this new threat in Princess Peach's Castle. This fight is unique because, as Shrowser says, the player cannot attack. In order to defeat Shrowser, the player must Jump over or hit back with the Hammer 20 fireballs, 10 fire orbs, or a combination of both, in order to destroy purple mushrooms, which indicate Shrowser's life. After destroying all mushrooms, Elder Princess Shroob will disappear, causing Bowser to lose his power. While Bowser is possessed, he looks pretty much the same, the only difference is that he's flashing green and purple and Elder Princess Shroob is floating above him.