Rookie

"For some reason, fighting these guys... Makes my gut flare up something fierce..."

- Rookie

Rookie is Bowser's amnesiatic alter ego. Popple's accomplice, Rookie has appeared only in Mario & Luigi: Superstar Saga.

Rookie is more or less the same as Bowser, even adopting Bowser's attacks from Super Mario Bros. He differs from his mentally natural counterpart physically, however, in that he wears a dark blue mask over his upper head and, strangely, has green eyes (whereas Bowser's as shown as red in Mario & Luigi: Superstar Saga). Rookie's personality is also different than that of Bowser; Rookie is extremely submissive and loyal to Popple.

Important to Rookie's story is that of Bowser in Mario & Luigi: Superstar Saga: After attempting to take Mario and Luigi to the Beanbean Kingdom in his Koopa Cruiser, the Koopa King found himself stuck in Tolstar's cannon. Just as Mario and Luigi earned the ability to free Bowser, Sergeant Starshade, angered with his complaining, blasted him to parts unknown. Later on, Popple would mention nursing a "dazed and lost" Rookie to health after finding him on "the mountain," apparently Bowser's impact site.

Mario and Luigi would first meet up with Rookie in Chateau de Chucklehuck, shortly after seeing Popple for the first time. Distressed at being seen and wanting the Chuckola Reserve, which he knew the Mario Bros. were looking for, for himself, Popple ordered Rookie to battle. After a brief cutscene in which Rookie expressed ambiguous recognition of Mario and Luigi, a fight did commence, with Rookie attacking with hammers, and, later, his fire breath. He proved to be very protective of his master in this battle, earning an extra attacking turn each time Mario and Luigi attacked Popple. Of note is that, if Mario and Luigi defeated Rookie before Popple, Popple would give up and run away, but Rookie must still be defeated if Popple is defeated first. (Defeating both earns more Experience Points.)

After the battle, Popple reprimanded Rookie for being unable to destroy the brothers, and the two ran off in hopes of getting to the Chuckola Reserve before the Mario Brothers. They were successful in doing this, but were unable to seize the soda for themselves: It apparently attacked them, and they were left tied up in barrels inside Mother Chuckalola. When the Chuckolator, the Reserve's living form, attacking Mario and Luigi, however, it ruined its own work by knocking Rookie and Popple loose, and their barrels landed in areas unknown.

Rookie would be fought for a final time at Woohoo Hooniversity. In a cutscene before the fight, Rookie showered his boss with praise as he lamented on his luck in the Beanstar falling right before him in the college's basement. However, Mario and Luigi soon showed up to bring the wish-granting star back to its rightful place, and Rookie excitedly followed his boss's command into battle. Rookie's battle pattern was identical to that of before, but he and his boss had since mastered the Bros. Attack, and would show their abilities to Mario and Luigi if the battle raged on with both on the field long enough. (Rookie could also now breathe fire from the start.) Their Bros. Attacks included a shockwave move done by Rookie pounding Popple to the ground and a projectile attack involving a flaming Popple. Once more, only Rookie needed to be defeated for the fight to end, but defeating Popple first and then Rookie earned more Experience Points.

Rookie and Popple would be knocked senseless after this fight, being unable to make any major reaction until a malfunctioning Peach-bot crashed into the battle chamber. Repeating its lines in Birdo's voice, the robotic Peach drove the Beanstar mad, and Popple, Rookie, Mario, and Luigi all grabbed onto it to stall its flight away. They slowly all fell off, and Rookie, finally remembering that he was "Bowser the King," was the last.

Bowser as Rookie would not be seen again, and Popple fought alone in his next encounter with the Mario Bros. However, the Shadow Thief filled the then-open position of accomplice with Birdo, who he would call Rookie in Bowser's absence. Popple himself would end up having a taste of his own medicine and adopt the name "Rookie" after his last defeat at Mario and Luigi's hands; his Toad probation officer referred to him by that name as he did public service near Little Fungitown Embassy.