Mouser is a large, anthropomorphic mouse who wears sunglasses, gloves and boots. He is a resident of Subcon, the land of dreams. Not much is revealed about Mouser, though it is mentioned that he is prideful and utilizes his bombs to destroy good dreams.
Yume Kōjō: Doki Doki Panic
Mouser made his debut in Yume Kōjō: Doki Doki Panic. Mouser helped Wart to invade the secret world of a storybook with his bombs. He is fought three times in the game: in World 1-3, World 3-3 and World 5-3, with a powerful white Mouser with red shoes and gloves exclusively appearing in the latter level, taking seven hits to defeat.
Super Mario series
Super Mario Bros. 2
In Super Mario Bros. 2, Mouser appears twice, one, with pink ears and shoes, in World 1-3 and the other, with green ears and shoes, in World 3-3 (The differing colors are only in the NES version.). The fight in World 5-3 of Yume Kōjō: Doki Doki Panic was replaced by Clawgrip. In battle, Mouser throws bombs at the player, which will explode after a short time. In order to injure Mouser, players need to grab one of these bombs and throw them back at him so that it explodes near or on the rodent; doing this several times (He takes three hits in World 1-3, and five in World 3-3.) will defeat him.
In Super Mario Advance, a new boss, Robirdo, replaced his second battle in World 3, which itself replaced Tryclyde's second battle in World 6; Tryclyde remained the boss of World 2. Like the main cast and the various bosses, he was given voice acting. His lines were performed by Charles Martinet, who voiced him with a snide tone. Upon defeat, Mouser can be heard exclaiming, "No way!"
BS Super Mario USA
In BS Super Mario USA, Mouser, Birdo and Wart have returned to Subcon to invade it again. Mouser is found in World 1-3 as the main boss of the world. He is no different than in the original game. However, like Wart and the Birdos, he could cast his own magic spell; such as turning enemies and objects into bombs, and throwing giant bombs out of nowhere.
The Super Mario Bros. Super Show!
Mouser is a prominent villain in The Super Mario Bros. Super Show!. Unlike his appearance in Super Mario Bros. 2, Mouser works as second-in-command under King Koopa rather than being a part of the 8 bits. Like Koopa, Mouser has many aliases that often match the general theme of the episode in which he appears. His main method of attacking is to throw either bombs or Bob-Ombs.
In this episode, Mouser is referred to as Sheriff Mouser, wearing a purple bandanna around his neck, a brown cowboy hat, and a star-shaped badge.
Sheriff Mouser first appears to surprise Mario, Luigi, and Toad when they walk up a hill. He attempts to arrest them with a band of Snifits and Ostros. After fleeing, Mario and his friends encounter and jump across a waterfall. Mouser attempts to jump by claiming, "If they can do it, so can I!", hesitating, and then nervously saying that his cronies can go first. After they fail and fall into the waterfall, Mouser begins to cry.
After Mario and friends go to a mine where Princess Toadstool is trapped, Mouser surrounds them with his band and tells them to "reach for the sky." However, a Tweeter then gets into an argument with him, distracting him, and Mario and co. quickly run away. Mouser then throws a bomb at the mine, and a resulting boulder chases Mario and co. Eventually, they get exhausted, fall for a trap, and are captured.
Mario and Luigi hatch a plan to trick Mouser by begging for water. He brings a glass, only to drink it in front of them. Mario and Luigi then play a game of Patty Cake, and Mouser exclaims, "Hey! What are you loonies up to?" Mario then knocks Mouser's hat off, allowing Toad to sneak inside. Mouser puts the hat back on, unaware of Toad's presence.
Mouser then arrives at a bar for a drink. Toad sneaks from the hat and steals Mouser's bombs to bomb Mario and Luigi's jail cell. When Mouser notices that Mario and his friends are free, he orders his pack of Koopa Troopas to stop them. Mario and Luigi run to the mine where Princess Toadstool is trapped, and Mouser allows Kid Koopa, an alias for King Koopa, to stop them. However, Koopa fails, and the princess is rescued.
In this episode, Mouser is referred to as First Mate Mouser, wearing a dark purple bandanna, glasses with one half broken resembling an eye patch, and a red-and-white striped shirt.
First Mate Mouser appears from below deck to report to Captain Koopa, another of King Koopa's aliases, that he has found no trace of any stowaways. Not satisfied with this, Koopa violently shoves Mouser aside and ventures below the deck of the Sinister Star. Later, he keeps lookout with a telescope. Seeing a rival ship named the Ding Bell, Mouser proceeds to alert Koopa of this. Grabbing the telescope from Mouser, Koopa sees Mario and Luigi riding the Ding Bell; furious, he throws his telescope to the ground and stomps on it.
King Koopa orders Mouser to bring him a Black Pit Bob-Omb; hesitantly, Mouser brings forth a chest containing an enormous Bob-Omb and passes the explosive to Koopa.
Mouser is next seen with King Koopa looking quite bored before noticing the Ding Bell yet again. after it crossed the pit. Koopa, in his frustration, throws his telescope at Mouser and proceeds to stomp on it again when it lands on the ground.
When Koopa subdues the Mario Bros. later, Mouser helps him force Mario to walk the plank.
Mouser retains his normal appearance in this episode, and is part of the Team Koopa that opposes Mario and Luigi, along with Tryclyde and a Koopa Troopa. Mouser's taunting at their first encounter with Mario and Luigi causes Team Koopa to laugh so hard, it lets the brothers drive away on their motorcycle unnoticed.
Mouser and his team are instructed by King Koopa to attack Mario and Luigi when they reach Dead Man's Curve. They soon find Toad and Princess Toadstool, who had been trying to catch the brothers' attention, and capture them both. As Mario and Luigi leave the Pasta Pit after a large meal, Mouser and his team ambush them and knock them from their motorcycle. As the brothers drive up a cliff, Team Koopa drives directly towards them, causing them to get distracted, hit a rock, and fall off the cliff. When they miraculously climb back up and continue driving, Mouser and Team Koopa activate speed-increasing devices in their vehicles, allowing them to quickly approach the brothers again.
After Mario throws an open can of tomato sauce at Team Koopa, Tryclyde and the Koopa Troopa lose control of their vehicles. Mouser however, appears and begins to assault the brothers with Bob-Ombs. Unfortunately, he soon becomes disoriented in the explosion of one of his own projectiles. Just as Team Koopa surrounds the brothers, Mario and Luigi play a game of Patty Cake, distracting them. The brothers flee to a nearby Vegetable patch and throw vegetables at Team Koopa. Mouser is hit by a large zucchini, knocked off his vehicle, and badly injured. He and the rest of Team Koopa are not able to continue racing.
In this episode, Mouser is referred to as Astro Mouser, wearing a purple jumpsuit and space helmet.
On the planet Quirk, Mouser throws a bomb at two Quirks, the planet's inhabitants, and demands they work harder and faster. Soon after, Mario's spaceship, after being forced to land by an array of meteors, crashes on top of a dumbstruck Mouser. The Quirks come to thank Mario and his friends for subduing Mouser, who slides out of the ship, appearing squished. Mouser then growls and throws squished Bob-Ombs at Mario and co. while they escape with the Quirks on a raft. He throws a Bob-Omb in the river, which springs a leak on the raft. Mario fixes the leak, however, which propels the crew away from Mouser. Mouser then alerts King Koopa about Mario and his friends entering the planet.
Mouser retains his normal appearance in this episode, and is first seen in Car Land on a cliff with King Koopa just as State Troopa surrounds Mario and his friends. Koopa tells Mouser about his plan to sell stolen spaghetti sauce from the rebels of Car Land.
Later, King Koopa orders the Koopa Pack, consisting of Mouser and several State Troopas riding cars, to siege the Rebel Fort. Mouser is knocked down from his car by Vegetables. He regretfully informs Koopa that Mario, Luigi and Toad have evaded capture, and soon after plots to annihilate them with his ultimate weapon, the Thunder Birdo. It bombards the Rebel Fort with a giant egg, causing an explosion, as an excited Mouser persuades King Koopa to overrun the fort, now in shambles.
During the race between Toad and King-of-the-Road Koopa, Mario and Princess Toadstool are surrounded by State Troopas, Mouser, and Thunder Birdo. Toadstool throws a bag of Bob-ombs into Thunder Birdo's mouth, causing it to explode and launch Mouser into the air. When he falls back down, Luigi throws a Bob-Omb directly at his face, sending him careening over the horizon. Mouser is not seen again for the rest of the episode.
List of episodes featuring Mouser
Nintendo Comics System
In the Nintendo Comics System, Mouser is said to have been the leader of similar looking rats called Mice, before defecting to King Koopa.
"A Mouser in the Houser"
In the Nintendo Comics System issue "A Mouser in the Houser", it is revealed that the Mice once had a prosperous society, having dug the Transport Tube system and hidden all the treasures they found in it. Eventually, the society of the Mice began to crumble when their king, Mouser, abandoned them and joined Bowser.
In the aforementioned comic "A Mouser in the Houser", several Mice abduct Princess Toadstool after she becomes lost in the Transport Tube system. After kidnapping the princess, the Mice reveal their origin to her and offer her the position of their queen, saying that if she agreed to this proposal, she could have a map of the Transport Tube system, as well as dozens of ready troops to help her defeat Bowser. Princess Toadstool eventually rejects the offer of becoming queen of the Mice when they refuse to help her aid Mario, who was being attacked by Mouser.
"The Buddy System"
In a later issue of Nintendo Comics System entitled "The Buddy System", a large group of Mice appear to capture Mario and Bowser when the two become lost in the Transport Tube system. Shackling Mario and Bowser together, these Mice interrogate them and learn that Bowser had planned on flooding the Transport Tube system by blowing up the main water valve of it. Deciding to aid Bowser in his plot of destroying the Transport Tube system, this group of Mice use bombs to blow up the main water valve, which causes a large amount of water to flow through the Transport Tube system and wash them away.
"Bedtime for Drain-Head"
Though several Mice appear on the alternate cover of another Nintendo Comics System comic entitled "Bedtime for Drain-Head", no Mice actually appear in the story.
Super Mario Bros. & Friends: When I Grow Up
In Super Mario Bros. & Friends: When I Grow Up, Mouser briefly appears as a disk jockey in the "Disk Jockey" career page. The page states the following:
Super Smash Bros. series
Super Smash Bros. Brawl
Super Smash Bros. Ultimate
Mouser appears as a Novice-class Grab-type primary spirit in Super Smash Bros. Ultimate. When used, it boosts the fighter's power without granting any special effect. In World of Light, the spirit is found on the Light Realm map. The spirit battle takes place on the Battlefield form of the Mushroom Kingdom II stage, with Pikachu as an opponent and Bob-ombs as the only items that spawn.
Mouser, like the rest of his species, is an anthropomorphic mouse that wears sunglasses that covers his eyes in most cases. When his eyes aren't covered, it is shown to be a white eye with a black pupil. He has gray fur, pink ears, a fur-less snout with a full set of teeth, and a fur-less tail. In Mouser's normal appearance, he lacks clothing, except for red gloves, red shoes and his sunglasses. Mouser does take on aliases, like King Koopa, where he wears an outfit to match the theme of the episode and he gets mentioned by a title, such as First Mate Mouser. In the show, Mouser has a Swiss accent, which is indicated by saying "zat" instead of "that" and other phrases where it is clearly defined. There are also references to his love of Swiss cheese.
In the cartoons, Mouser, like his boss, King Koopa, is an antagonist of Mario and his friends and he will do anything he can to capture them. Mouser also likes to use bombs as his primary form of attack. Even though he is second-in-command, his pack members still obey him, as seen in "Butch Mario & The Luigi Kid." Mouser, however, does laugh at King Koopa when something embarrassing happens to him, as demonstrated in the episode, "The Adventures of Sherlock Mario" when Herlock Solmes recalls King Koopa's embarrassing memories of his past, though he is still afraid when King Koopa threatens or gets angry at him.
Super Smash Bros. Brawl sticker
Super Smash Bros. Ultimate spirit
Names in other languages