I'll be taking that, see?
Popple, Mario and Luigi: Superstar Saga.
Popple is a villain in Mario and Luigi: Superstar Saga. He is a wannabe thief who has had many rookies. His first Rookie was amnesiac Bowser, his second was Birdo. Popple also calls himself the "Shadow Thief.
Popple was first encountered in Chucklehuck Woods trying to steal the secret of the brewery's world famous drink, Chuckola Cola, with his partner Rookie (who was really Bowser who apparently lost his memory from being shot out of a cannon in Stardust Fields and didn't recognize the Mario Bros). Popple and Bowser fight Mario and Luigi. After being defeated, the Mario Bros. continued their adventure. Popple and Rookie were seen again before Mario and Luigi fought the Chuckulator. However, they were shot away by it.
Popple is seen again in Wohoo Hooniversity trying to steal the Beanstar. When Mario and Luigi battle him, Popple and Rookie have a Bros. Attack. Their attack is for Rookie to flame Popple and throw him in the air, while Rookie creates shockwaves on the ground, then hurls Popple at the bros. After being defeated, a Peach Bot suddenly falls in the room and makes the Bean Star go crazy and Popple, Rookie, and the Mario Bros. grab on to the star, but they all fall off and Popple gets separated with Rookie. The Bean Star then shatters into four pieces. Popped landed likely in Chucklehuck Woods. When Mario and Luigi revisit Chucklehuck Woods to get a piece of the Bean Star, Popple is trying to steal the Beanstar piece. This is the first and only time he is battled alone. In this battle he has much higher defense. He also has the ability to steal Mario or Luigi's Hammers. After being defeated, Popple runs away underground, swearing revenge.
Popple is found again in Teehee Valley, underground. This time, Popple has a new Rookie, Birdo, who "loves" Popple, and Popple gets very freaked out about it. Mario and Luigi fight the thief again and after being beat, Popple is sentenced to community service in Little Fungitown, and, ironically, his partner calls him Rookie.
Popple wasn't seen again until Mario and Luigi: Dream Team. He will be heard robbing a building in Wakeport, when he sees nothing he wants. Luigi tries to walk into the building, when he and Popple crash into each other. Popple would get mad at the bros, then becomes calm and goes away.
Popple is now found still in Wakeport at Wiggler's garden, insulting Wiggler. The Mario Bros. go into the garden. (But, you might want to save a Pi'illo before you meet up with them.) When you meet up with them, Popple would say that with the help of Mario and Luigi, Wiggler would be gone. Wiggler gets mad because Popple called him a moth. Popple will go first by pulling Wiggler's flower on his head. He'd get mad and make waves at the bros. Wiggler flings Popple off of him. Hammer him onto Wiggler.