Elder Shrooboid

The Elder Shrooboid is a red Shroob with yellow spots and spikes on top of its head in Mario & Luigi: Partners in Time. It is the strongest of all Shrooboids. Mario, Luigi, Baby Mario and Baby Luigi fought this powerful Shroob at the Star Shrine high above the Mushroom Kingdom. Before the battle, the Elder Shrooboid incapacitated Toadbert and Kylie Koopa, and stole the Toad's Cobalt Star shard. When the Mario Bros. arrived, Toadbert attempted to reveal the truth of the Cobalt Star and the Elder Princess Shroob trapped inside by having Mario rub off the dirt on his strange sketch he had made awhile beforehand, thus revealing two Princesses, but he, along with Kylie Koopa, were turned into purple Shroob mushrooms by the Elder Shrooboid. Hoping to gather all the shards and awaken its leader, the Elder Shrooboid attacked the Mario brothers.

During the battle, the Elder Shrooboid used a variety of attacks against the four Mario Bros. of past and present. First, the Elder Shrooboid would trap Mario and Luigi in crystals (like the Shroids) and run off to grab a heavy metallic ball on a chain. As the Mario Bros. jumped to break their crystal imprisonments, the Elder Shrooboid would spin the ball and chain towards the heroes. The spinning would cause the Shrooboid to get dizzy, drop the ball, and fall down. However, the Elder Shrooboid would soon stand up, knock the ball into one Mario brother then lunge head first into the other Mario brother. The metallic ball would either have an "M" (for Mario) or an "L" (for Luigi) painted on it, indicating which Mario brother the ball would be used against. As such, the appropriate Mario brother had to jump over the metallic ball while the second Mario brother had to jump over the lunging Shrooboid. If a Mario brother could not break his crystal prison fast enough, the hero could not avoid the Elder Shrooboid's attack.

Additionally, like the Junior Shrooboid, the Elder Shrooboid could perform a spin attack against a Mario brother. The corresponding Baby Bro. could counter this attack with a Hammer strike. However, the Elder Shrooboid would keep coming back, meaning the Baby Mario Bro. had to counter multiple times. The Elder Shrooboid could also shoot fireballs (like the Blazing Shroobs) from its hands at the Mario brothers. In fact, the monster could even shoot two fireballs at once. Mario and Luigi could jump to dodge these fireballs. Since the Elder Shrooboid had spikes on top of its head, jump attacks were ineffective against the monster. As such, Baby Mario and Baby Luigi had to use their Hammers to deliver damage to the Elder Shrooboid.

The Elder Shrooboid could also create a spiked ball which it would then throw towards the Mario Bros. The ball would circle around the brothers (like a Love Bubble) until closing in on one brother and striking, moving faster and faster which each orbit. If hit, the brother would be damaged and possibly poisoned. The ball could be deflected with a properly timed Hammer strike, sending the spiked weapon flying off into the air. After seeing this attack deflected, the Elder Shrooboid would gasp and fall over from shock. When on the ground, the Elder Shrooboid became vulnerable to jump attacks, and any attack would do more damage than usual.

Eventually, after much fighting, the Elder Shrooboid started to shrink into nothingness, but surprised the Mario Bros. by instantly growing to humongous proportions. When in this state, the Elder Shrooboid had the same attacks as before, but the attacks were faster, more powerful, and giant-sized to fit his new body. Additionally, after becoming gigantic, the Elder Shrooboid released a Shroob UFO from its mouth. This UFO held a sign with the number four on it, indicating to the Mario Bros. that they only had four turns left to defeat the Elder Shrooboid. If they could not defeat the monster in four more turns, the Shroob UFO would fire a massive energy blast, instantly defeating all four Mario Bros. The Mario Bros. could deflect the Elder Shrooboid's spiked balls at the Shroob UFO, resetting the counter back to four turns. When Baby Mario deflected a spiked ball, the weapon would fly above the Elder Shrooboid, but when Baby Luigi deflected the ball, the spiked weapon would fly above the Mario brothers. Since the Shroob UFO changed positions in the air during the battle, only one of the Baby Mario brothers could deflect the weapon to reset the counter. If the UFO was above the Elder Shrooboid, Baby Mario had to deflect the spiked ball. If above the four Mario brothers, Baby Luigi had to deflect the spiked ball.

Ultimately, the four Mario brothers destroyed the Elder Shrooboid and recovered the fifth Cobalt Star shard. Although their friends were transformed, the heroes had to continue their fight against the Shroobs. With their fifth star shard, Mario and Luigi could finally enter Shroob Castle, the Shroobs' base of operations on Mushroom World. Leaving the Shroobified forms of Toadbert and Kylie Koopa behind, the four Mario brothers returned to Princess Peach's Castle in the future to prepare for their final campaign.