Bowser's Inside Story
The Elite Trio first appear in Dimble Wood moving a Banzai Bill Cannon that they plan to fire at Bowser's Castle which was currently under Fawful's custody. However, they lacked ammo, prompting Bowser to find one for them. Once Bowser obtains a Banzai Bill from Wiggler, the three fire the cannon, only for the castle to fly towards the site and crush Bowser and the cannon. When Bowser grows giant due to the Mario Bros. boosting his adrenaline to bring him back to life, the trio observe the battle, with Corporal Paraplonk teaching Bowser how to fight in giant battles.
Later, while finding the Star Cures, after exiting the Tower of Yikk, Bowser spots Private Goomp wandering about, telling his king that one of the cures resided in his treasure chamber beneath his castle. Bowser then rushes off leaving Private Goomp behind. In the treasure trove, after Bowser obtains the second Star Cure from a safe, the trio tell Bowser to look back in the safe. With his back turned, the three push Bowser into the safe, revealing that they now serve Fawful who promised them extra rations. They then take the safe to Peach's Castle, which was also under custody of Fawful.
After the credits of the game, while Bowser is bedridden after being defeated by the Mario Bros., the Elite Trio arrive and apologize for their betrayal, asking to rejoin the Koopa Troop. Bowser responds that he will pardon them if they help with the repairs on the castle, which they go off to do.
It is revealed that the trio have been promoted to Bowser's royal guards (having the word Elite in their name) and arrive with Bowser and Kamek to Pi'illo Island to capture Princess Peach. In Dreamy Driftwood Shores, while expanding the layers of the Dream World for Peach to be safe from Bowser and his minions, it is revealed that the "Peach" that Mario and Imaginary Luigi were guiding was actually Kamek, having kidnapped the real one back in the real world of Driftwood Shores. He summons the Elite Trio to fight Mario, only for them to lose. In anger, Kamek demotes them to janitors, much to their disappointment.
In Neo Bowser's Castle, after the Mario Bros. defeat Antasma, the trio roll giant Bob-ombs down the spiraling ramp to prevent the Bros. from getting to Bowser. Once the Bros. reach the top, the trio charge at Mario and Luigi, only for them to move to the side and send them falling to the bottom of the ramp.
During the credits, while Bowser and the troop return the Mushroom Kingdom, Bowser praises the trio that they did well for their usual standards, much to their joy. When the Zeekeeper breaks the Dream Coin causing thousands of coins to scatter, Private Goomp and Seargent Guy cause the Koopa Clown Rock to rock so much while collecting raining coins that it falls into the ocean, prompting Kamek and Corporal Paraplonk to rescue them.
Superstar Saga + Bowser's Minions
In Minion Quest: The Search for Bowser, it is revealed that Private Goomp was one of the first two Goombas that Mario and Luigi fought on the Koopa Cruiser alongside Captain Goomba, sparking a rivalry between them. In the level "Goombas vs. Goombas", when Captain Goomba confronts Fawful and demands him to return Bowser. Private Goomp appears and tries to defeat Fawful himself, only to be brainwashed by gas that comes from Fawful's headgear. Captain Goomba defeats Private Goomp, but Fawful gets away. Later in the Beanbean Kingdom level "The Rival Trio", Private Goomp returns with his teammates in training, Corporal Paraplonk and Sergeant Guy to form a trio and battles Captain Goomba and his team for copyright infringing his "plan" to save Bowser. After the battle, the trio argue over their leadership skills, prompting Captain Goomba and his Squad to make their leave.
Later in the level "Silly Ol' Goomp" in Teehee Valley, Private Goomp challenges Captain Goomba to a battle due to them infringing his goals. After Goomp loses, Captain Goomba forces him to join his team, but he escapes later on. In the Joke's End level "The Trio's Last Stand", the trio set a time bomb on the Koopa Cruiser to get back at Captain Goomba and the Goomba Squad. After defeating the trio for the last time and deactivating the bomb, Private Goomp decides to settle his rivalry with Captain Goomba and calls a truce, making the trio join Captain Goomba's team.
Private Goomp is a melee type and his ability is Rocket Headbutt, making him deal a powerful headbutt to a single enemy. Corporal Paraplonk is a flying type and is ability is Cranium Crush, which is similar to Captain Koopa's Shell Shock in that he uses his shell to damage multiple enemies at the cost of temporarily becoming dizzy and lose defense. Seargent Guy is a ranged type and his ability is Sure Shot, increasing the accuracy of the team.
Bowser's Inside Story + Bowser Jr.'s Journey
The Elite Trio play the same role in the main game. In Bowser Jr.'s Journey, the trio only appear in the post-game, where Bowser's comrades have shunned them for their betrayal and claim that they must "earn back their trust". Bowser Jr. believes their treason was from Malatone:X and challenges them to battle. After their defeat, the Koopa Troop welcome them back in and they join Jr.'s army, while having to be Bowser Jr.'s new punching bags. They have the same types and abilities as in Bowser's Minions.
The leader of the Trio, Private Goomp is a Goomba that wears a blue shirt and cap, resembling pajamas. He has a personal rivalry with Captain Goomba.
Corporal Paraplonk is a Koopa Paratroopa with green shoes, a red shell, and a red bucket on his head that serves as his helmet.
Sergeant Guy is a green Shy Guy that carries a backpack with a silver pipe and Magikoopa wand. In Dream Team, he also carries a Bowser flag.
- In Dream Team, the Elite Trio wear special black equipment with Bowser's symbol on it to represent their positions as Bowser's royal guards, these include Private Goomp's cap, Corporal Paraplonk's bucket helmet, and a flag in Sergeant Guy's bag. After being demoted, they go back to their regular outfits.
- The special black equipment shows up in Minion Quest: The Search for Bowser, despite the trio not being promoted to Elites. This is an oversight on the part of Nintendo.