Commander Shroob is a pink Shroob with a black mustache and a whistle. He is encountered during the events of Mario & Luigi: Partners in Time. He is the commander of the Shroob occupation forces during their invasion of the Mushroom Kingdom. Commander Shroob is confronted and ultimately defeated by the four heroic defenders of the Mushroom Kingdom past and present: Mario, Luigi, Baby Mario, and Baby Luigi.
The battle between the four Mario Bros. and Commander Shroob takes place on Star Hill. During the confrontation, Commander Shroob commands his loyal Support Shroobs from behind the scenes, allowing his soldiers to fight the heroes while avoiding personal injury. However, the Mario Bros. are able to send the massive Shroob-omb rolling backwards. The bomb then explodes, knocking Commander Shroob into the battlefield.
However, even when forced to battle, Commander Shroob's primary attack is calling his Support Shroobs into the battlefield and launching them at the Mario Bros. Some are sent twirling on the ground, while others are sent flying in the air. While in the air, if a Support Shroob is pointing up, the Shroob falls on top of Mario. If it is pointing downwards, the Support Shroob falls on Luigi. The Support Shroobs can be blocked with swings from the Mario Bros.' Hammers. Occasionally, Commander Shroob approaches the Mario Bros. and shoots them with his ray gun, just like a normal Shroob soldier. It is much faster than a regular Shroob ray gun, however.
Eventually, armed with a Shroob-omb sign, Commander Shroob directs three more Support Shroobs and a Shroob-omb into the battlefield to continue the fight while he goes back into hiding. As such, the Mario Bros. have to knock more Shroob-ombs backwards to send Commander Shroob back into the fray. In the end, Commander Shroob's tactics are not enough to defeat the Mario Bros.' teamwork and the Shroob's military leader is defeated in combat.
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