Bowser Jr.

The misguided prince who fights to make his father proud.

Bowser Jr., known in Japan as Koopa Jr. and simply as Junior, is the sole child of Bowser and a secondary antagonist within the Mario franchise. Introduced in Super Mario Sunshine in 2002, he serves as the prince of his father's kingdom. Unlike traditional villains, he operates out of a misguided desire to make his father proud rather than inherent malice. Skilled in magic, technology, and invention, Jr. often aids Bowser's evil plans based on false beliefs indoctrinated by his dad, such as thinking Princess Peach is his mother and Mario is a bad man.

Quick Facts

Series: Mario
Creator: Shigeru Miyamoto
First game: Super Mario Sunshine (2002)
Nickname: Junior
Species: Koopa
Family: Bowser (father)

Lore & Background

Storywise, Bowser Jr. is a child prodigy who believes he must rescue Princess Peach because his father told him she was kidnapped by Mario. This misunderstanding drives his actions in Super Mario Sunshine, where he utilizes a magic paintbrush invented by Professor E. Gadd and a giant robot of his own creation to fight the plumber. Even after the final battle reveals that Peach is not his mother, Jr. remains determined to defeat Mario to help Bowser.

Development teams later focused on him for titles like Bowser's Journey to show his growth from living in his father's shadow to leading a gang he cherishes. In The Super Mario Galaxy Movie, voiced by Benny Safdie, the character is depicted as a spoiled, angry child obsessed with his dad, featuring bonding dialogues like "Oh, daddy" and "Oh, daddy, please." Shigeru Miyamoto confirmed in 2012 that Jr. is Bowser's only child, though the mother's identity remains unknown.

Reader's Guide

Bowser Jr. appears as a recurring boss in mainline titles including New Super Mario Bros., New Super Mario Bros. Wii, Super Mario Galaxy 2, New Super Mario Bros. U, and Super Mario Bros. Wonder. Beyond the core series, he is a staple in spin-offs like Mario Kart, Mario Golf, Mario Tennis, Mario Party, and Mario and Sonic at the Olympic Games. He made his debut in the Paper Mario series with Sticker Star and appeared in Mario & Luigi: Dream Team before receiving a dedicated side story, Bowser's Journey, in the Nintendo 3DS remake of Mario & Luigi: Bowser's Inside Story.

In the Super Smash Bros. franchise, he debuted as a playable fighter in Super Smash Bros. for Nintendo 3DS and Wii U. His design is consistent across media: a bipedal turtle-like creature with a yellow body, beige snout, green spiked shell, and a white bandana displaying a jagged mouth. In The Super Mario Galaxy Movie, his design was modernized with a mechanized voice, metallic armor, and a transformable paintbrush capable of shifting into a chained morning star.

Did You Know?

In a 2015 interview regarding Bowser Jr.'s mother status, Shigeru Miyamoto humorously claimed it to be himself.
Bowser Jr. was chosen as the protagonist for Bowser's Journey because developers felt he offered a different appeal compared to Goomba or Bowser in previous games.
In November 2025, critics noted Bowser Jr.'s bloodshot eyes in The Super Mario Galaxy Movie as an artistic device reflecting fatigue or emotional instability.