Larry

"It's about time for us to get a taste of revenge from these pesky plumbers!"

Larry Koopa is one of the Koopalings. He's the youngest of them all, and he has quite the insidious mind, helping others to mainly scheme the future plans of Bowser. But sadly, his plans mainly blast on his face, and his consequences are the most dire. He isn't exactly childish despite being the youngest, but whenever he sees something funny for his sick humor, he never hesitates to laugh. He is voiced by Lani Minella.

History
Larry Koopa has first appeared in Super Mario Bros. 3, as the first boss fought in the game. He later appeared in Super Mario World and New Super Mario Bros. series as of the Wii installment, remaining as a Koopaling with simple tricks.

Like his siblings, he also appears in Mario & Luigi: Superstar Saga and Paper Mario: Color Splash as a boss.

In Prismverse Saga
Larry Koopa first appears in SMATSP as a mid-boss, supporting Bowser Jr. with his siblings from Bowser's Clown Car. After their defeat, Larry willingly stays behind to protect the castle, as he bravely chooses not to give in his only home.

His future appearances are unknown, but it's confirmed that he'll be fought individually at some point in a future episode.

Trivia

 * The inspiration of Larry's name isn't taken after someone famous, as it's stated that he looks like an average "Larry".
 * In Super Mario World's guidebook, Larry was referred as "Bowser's number one Koopaling".
 * He has the same voice actor as Morton, Wendy and Lemmy.

Lore
Larry Koopa is the youngest among the Koopalings, and possesses quite the mind of a sly thinker. His past is unknown, as his previous family before being adopted. As he was adopted at such a young age, he can remember his days at Bowser's Castle: Usually setting up the games the Koopalings played, or playing as the villain in their games. His days as a child was bright.

But when the Koopalings grew old enough to join their father in his schemes, Larry was the most excited, as he was still a child. But after his first defeat in Mario Bros' hands, he knew war wasn't a child's play. He needed to be serious and grow up. So, in his later days as a soldier, he took part in more serious schemes: Like trapping a good amount of Yoshi Eggs, hijacking a train and taking down various enemies from afar as a sniper.

Despite he's still young, his mind is still fresh, and Larry has still a lot to learn before he can become a great leader in his schemes.