|“||Oh, you think you're so smart, teaming up on me, huh? Don't think you can beat me just cuz I'm alone. It's my solo debut on the battle lines, see?||„|
Popple is a major antagonist in Mario & Luigi: Superstar Saga. He also appeared in Mario & Luigi: Dream Team as a minor antagonist and in Mario & Luigi: Superstar Saga + Bowser's Minions for the Nintendo 3DS.
Mario & Luigi: Superstar Saga
Popple, or the "Shadow Thief" as he calls himself, is a wannabe super thief who dreams of getting rich quick. Popple makes his first appearance when the Mario bros. bump into him after they exited through a maze of barrels in the Chateau de Chucklehuck where they were after the secret of the brewery's world famous drink, Chuckola Cola. As the Mario bros. followed Popple after discovering him, they ran into his accomplice, Rookie (who was really an amnesiac Bowser). Engaging the bros. in battle, Mario and Luigi managed to beat Popple and the blank-minded Bowser. After defeating them, the bros. free the brothers and owners of the Chateau de Chucklehuck, Cork and Cask from barrels, after Popple and Rookie trapped them in there. Cork and Cask then teach Mario and Luigi the Mini Mario and Luigi Dunk techniques with their hammers. Popple and Rookie showed up again when Mario and Luigi encountered the founder of Chuckola Cola, Bubbles, who reveals the two trapped inside barrels to the bros. before summoning the Chuckolator to blast them away.
The bros. encountered Rookie and Popple again in the basement of Woohoo Hooniversity, where they were trying to steal the Beanstar. The two groups ended up fighting again, and even when using their own bros. move, Popple and Rookie still lost. Suddenly after the battle, the head of a Peach robot fell through the ceiling and played its recording of Birdo's voice that irritated the Beanstar so much, it bursted through the ceiling, making Mario, Luigi, Rookie and Popple grab onto it as it flew through the air. The Beanstar then divided into four pieces flinging all its passengers off. Mario landed with Luigi in Oho Oasis, while Bowser was flung to Stardust Fields, then used as revival power for Cackletta's spirit. Popple's landing destination is unknown.
Popple appeared again in Chucklehuck Woods, trying to get a piece of the Beanstar off a statue. The Mario Bros. fought him again, but this time without Bowser. Popple appeared again having made a base in Teehee Valley. After finding an unconscious Luigi in the desert, he took him as a prisoner to lure Mario to his base. After Mario freed Luigi, Popple attacked and introduced his new Rookie, Birdo, who had fallen hopelessly in love with him. After losing in battle, Popple blamed his defeat on Birdo and called her useless. Heartbroken, Birdo knocked him through the wall. Popple was then sentenced to community service in Little Fungitown where he is last seen, and ironically, his supervisor calls him Rookie.
Mario & Luigi: Dream Team
Popple eventually makes his way to P'illo Isle in search for more valuables to steal. He is first seen attempting to steal from Pi'illoper's house in Wakeport, after a failed attempt to steal his artifacts. He is discovered by Mario and Luigi; while not recognizing them at first, he recalls that they look familiar to two others from the Beanbean Kingdom. He is later spotted in two tours, at Driftwood Shore and Mount Pajamaja. He leaves Driftwood Shore due to a lack of treasure, and at Mount Pajamaja he is kicked out by the Massif Bros. due to there being no room for him.
Back in Wakeport, Popple attempts to rob from Pi'illoper's house again from the back entrance. He is caught by the Mario Bros., but believes that they must be thieves as well. Popple decides to make the Mario Bros. his new Rookies and work together to defeat a Wiggler in the flower garden, mistaking him as a guard. However, after the Mario Bros. defeat the Wiggler, Popple quickly turns on Mario Bros. and fought against them, only to end up beaten as well. Afterwards, Popple discovers that Wiggler was no security guard and expresses his frustration by insulting the flower garden. Wiggler is enraged by Popple's insult and chases him away from P'illo Isle.
- Popple's role in the game is similar to Jr. Troopa and the Shadow Sirens as they all are fought more than one time.
- In Paper Mario: The Thousand-Year Door, a reference to Popple is made when Bowser visits Poshley Sanctum to steal the Garnet Star. When Pennington asks him who he is, one of the answers is "The Shadow Thief", which is what Popple calls himself. Also, if the player selects this title, Bowser will say "I'll be taking this, thanks!", a reference to Popple's "I'll be takin' that, see?", which in turn is a reference to Edward G. Robinson's character in films such as Little Caesar.