Shroob-omb

A Shroob-omb is a giant purple Shroob Bob-omb used by the Support Shroobs during their battle with the Mario Bros. of past and present. The Support Shroobs would toss the Shroob-omb at the Mario Bros., engulfing the heroes in an unavoidable explosion. After the explosion, another Shroob-omb would be dropped into the battlefield by a Shroob UFO. Shroob-ombs have extremely high defense, meaning it is almost impossible to directly destroy these massive bomb creatures.

Only three Support Shroobs are needed to lift one Shroob-omb effectively, indicating the bomb is extremely light. In fact, even two Support Shroobs can lift the Shroob-omb if one of the Shroobs is destroyed, although the two remaining Support Shroobs will flash red under the stress. Ultimately, if two Support Shroobs are destroyed, the Shroob-omb will prove too heavy for the sole remaining Shroob. This last Support Shroob will be crushed and destroyed under the weight, and the Shroob-omb will roll off, either into the Mario Bros. (if the back Support Shroob remained) or Commander Shroob (if the front one remained). The middle one is random, but is mostly towards the Mario Bros.

Trivia

 * In the Japanese and European versions of Mario & Luigi: Partners in Time, the Shroob-omb has the highest amount of HP for any enemy in the game, including the Elder Princess Shroob.
 * Although the Shroob-omb only has an average defense rating, the enemy is programmed to take 1 damage from any attack, as the Shroob-omb was not designed to be directly destroyed. However, if one does hit a Shroob-omb enough times to actually destroy it, the Support Shroobs will simply stop attacking until at least two one the Shroobs are defeated.  A Shroob-omb will then suddenly appear on-screen and either roll towards the Mario Bros. or the Commander Shroob as normally programmed, as if the Shroob-omb was never destroyed in the first place.  Additionally, if the player manages to destroy more than one Shroob-omb, the game will only award the Mario Bros. for destroying one (that is, the brothers will receive 0 Experience and 1 Coin for their efforts).
 * Dark Fawful Bombs from Mario & Luigi: Bowser's Inside Story heavily resemble the Shroob-omb.
 * Bob-ulk, a species of Bob-omb from Paper Mario: The Thousand-Year Door, also bears a resemblance to Shroob-omb.