Shadow Mario

"(Go ahead if you really think you can make it.)"

- Shadow Mario

Shadow Mario (also known as ? in the Super Mario Sunshine instruction manual) is a doppelgänger of Mario and serves as the main antagonist of Super Mario Sunshine. He is almost identical to Mario, with the primary difference being that his body is a translucent blue, appearing to have a liquid consistency. Other traits that are unique to Shadow Mario include glowing red eyes when he is angry and a long, red tongue that he occasionally sticks out at Mario while taunting him. Shadow Mario wields the Magic Paintbrush, an invention designed by Professor Elvin Gadd. With the brush, Shadow Mario can magically create large quantities of goop, which occasionally spawns lesser enemies. He used this power to vandalize all of Isle Delfino with varying amounts of graffiti, thereby making Mario the main suspect in the trial held thereafter. Later in the game, it is revealed that Shadow Mario is actually Bowser Jr., Bowser's son, masquerading as a Mario look-alike in order to steal Princess Peach and ruin Mario's reputation. It is unknown how Shadow Mario originally acquired the Magic Paintbrush, though it is suggested that Professor E. Gadd gave it to him. This is also supported in the Prima Games Guide for Super Mario Sunshine, which claims that E. Gadd gave the Magic Paintbrush to Shadow Mario due to thinking that he was Mario.

In the Super Smash Bros. series, the Koopalings are also capable of becoming Shadow Mario.

Super Mario Sunshine
In the opening introduction of Super Mario Sunshine, Mario, Princess Peach and Toadsworth are seen traveling to the island resort of Isle Delfino via Peach's private airplane. During the welcome video, a silhouette resembling Mario appears in the background, first running to behind the Grand Pianta Statue followed by jumping out from behind it, now holding the Magic Paintbrush. Princess Peach is the only one to notice this, as Mario and Toadsworth are more preoccupied with their thoughts about the island (with Mario in Heart Eyes thinking about tropical food, despite his love for spaghetti, and Toadsworth thinking about the usual vacation stuff, thus being resting in the sun).

Once the plane comes to a screeching stop and everyone gets off to look at the goop on the airway, Peach notices the Shadow Mario figure once again. She tries to get Mario and Toadsworth's attention, but Shadow Mario has already disappeared. Once Mario takes care of the goop with his newly obtained F.L.U.D.D., he is thrown in jail and put on trial, being accused of Shadow Mario's crimes of vandalizing the island. A Pianta judge orders Mario not to leave the island until he cleans up all the goop. Once Mario cleans up Bianco Square, the Grand Pianta Statue appears with Shadow Mario on top of it. He jumps from the statue, grabs Princess Peach, and runs off with her. Upon being sprayed enough times, Shadow Mario drops the princess, and then heads back to Bianco Square, opening up the way to Bianco Hills.

Shadow Mario's next major role in the game is when he kidnaps Princess Peach again, taking her to Pinna Park. Once Mario catches up with him, Shadow Mario will summon Mecha-Bowser, the boss of the current mission. Upon being defeated, he reveals his true identity as Bowser Jr., then takes off in a balloon to Corona Mountain with Princess Peach.

Shadow Mario appears in every seventh episode of every area and Mario must defeat him in order to collect the Shine Sprite he carries. Once all seven Shadow Mario episodes are completed, the entrance to Corona Mountain will open, as well as Delfino Plaza becoming flooded. Shadow Mario appears in several other episodes as well, though with a minor role. Also, whenever Mario enters a secret level area for the first time, Shadow Mario will appear and take F.L.U.D.D. away. F.L.U.D.D. will return to Mario once the Shine Sprite at the end is collected. Shadow Mario also takes F.L.U.D.D. away during the third episode of Pianta Village, The Goopy Inferno and can be recovered near the end of the episode mission.

After episode 4 of Pinna Park is completed, Shadow Mario will appear in Bianco Square carrying a Yoshi Egg. Defeating him will unlock Yoshi in several area episodes. Shadow Mario will appear two more times afterward when enough Shine Sprites are collected. He'll be carrying a Turbo Nozzle the first time and a Rocket Nozzle the second time, and defeating him will unlock those nozzles for use in Delfino Plaza.

The levels in which he appears are as follows:

Levels in bold are levels specific to Shadow Mario for that particular area.

Mario Golf: Toadstool Tour
Shadow Mario makes his first playable appearance in Mario Golf: Toadstool Tour as an unlockable character. In the game, his maximum hit is 275 yards, and causes the ball to curve to the right when hit. He also has a low shot, meaning lie has a greater impact on the ball. His shot is like that of Luigi's, with power almost able to match Mario's. He mostly uses edited voice clips of Mario from Super Mario 64, with a lower pitch and slight damping filter. In order to unlock Shadow Mario, the player must complete all of the Ring Attack holes. Bowser Jr. also appears as a separate playable character.

Super Smash Bros. Brawl
Shadow Mario appears as a collectible sticker in Super Smash Bros. Brawl. He also appears on a wanted poster in the Delfino Plaza stage.

Super Smash Bros. for Nintendo 3DS / Wii U
Bowser Jr.'s Final Smash in Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U is Shadow Mario Paint, which sees him transform into Shadow Mario and use his Magic Paintbrush to paint a giant orange X of graffiti that covers the entire screen and damages any opponents that come into contact with it. As the Koopalings are Bowser Jr.'s alternate costumes, they are able to transform into Shadow Mario as well.

Super Smash Bros. Ultimate
Shadow Mario reappears in Super Smash Bros. Ultimate as a part of Bowser Jr. and the Koopalings' Final Smash, but he is active for a shorter period of time. He also appears as a neutral, primary spirit, which can be summoned with a Vince, Eddy, and neutral-type core.

Other appearances
Shadow Mario's name appears on one of the scoreboards in Mario Golf: Advance Tour.

Trivia

 * Prior to Shadow Mario's debut, Metal Mario had an alternate color scheme where he can be selected into blue in Mario Golf for Nintendo 64, compete with an animated texture similar to water, except he lacks the red glowing eyes..
 * When Mario is chasing Shadow Mario, a cover version of the Underground Theme from Super Mario Bros. plays in the background. This music has come to be known as Shadow Mario's theme.
 * In Super Mario Galaxy, the music played when racing Cosmic Mario (who has a similar appearance to Shadow Mario) uses a similar arrangement of the same theme.
 * In any mission where Mario chases down his shadowy counterpart, if he waits 10 seconds after defeating Shadow Mario without talking to him, Shadow Mario will transform into a blue orb and teleport further away from Mario before restarting the chase, similar to a Magikoopa's current method of transportation.
 * As found within the game files, Shadow Mario shares the same animations as Mario and Il Piantissimo, with some extra ones added to accommodate that the two (Piantissimo and Shadow Mario) are NPCs.
 * In Super Mario 3D World + Bowser's Fury, the "M" signature returns in the opening of Bowser's Fury as a means of transporting Mario to Lake Lapcat.