Morton Koopa Jr.

Morton Koopa Jr. (also known as Big Mouth Koopa Jr.) is one of Bowser's eight children and is the sixth oldest Koopaling. Although he is the largest of the koopalings, Morton doesn't appear to be as powerful as some of his other large brothers, like Ludwig or Roy. This may just be due to the fact that he is one of the younger Koopalings, and needs to grow some more.

Unlike his siblings, many of Morton's features are unique, and are not shared traits. He is the only Koopaling to have brown skin, whereas the others all have orange skin. Morton is also the only one of his siblings to have a unique shell color. While his siblings have either green or pink shells, only Morton has a gray one. He is also the only one to have a white head. Another unique feature of Morton's is the large, star-shaped birthmark on the left side of his face (similar to the makeup worn by Paul Stanley of KISS fame, except the mark is on the left side of Morton's face, not right).

Super Mario Bros. 3
Morton's first appearance was in Super Mario Bros. 3 where he, along with his siblings (minus Bowser Jr.) aided their father in an attempt to take over the Mushroom World. Morton usurped the sultan of Desert Land and took over, but in the end he was defeated by Mario.

Super Mario World
Morton appeared again in Super Mario World helping his family in an attempt to take over Dinosaur Land. Morton's Castle was located in the second area, the Donut Plains. Morton attacked Mario by climbing the walls and ceiling of his room and dropping down, but once again, the battle ended in the Koopaling's defeat.

New Super Mario Bros. Wii
Morton appears as a boss once again, this time in New Super Mario Bros. Wii. He is fought on a platform with the ends of each side slightly raised up; it is set in a sea of lava, out of which Podoboo occasionally jump. Morton's main method of attack is that he shoots out explosive energy blasts that can be targeted in any direction; he can also do a Ground Pound that will stun anybody that is on the ground. Whenever Morton is damaged, he will jump into his shell and spin to attack, but this is easily avoided if the player jumps on the raised ground. Morton can be defeated if the player stomps on him three times, or if they throw a certain number of fireballs at him. After he is defeated, he (and potentially the other Koopalings as well) escapes. His world is World 6.

Super Mario anime series
Morton, along with the other Kooplaings appeared in two of the Japan-only Super Mario anime videos. In Momotaro, they try to defend their father's castle, only to be defeated by Mario and his friends in their quest to rescue Princess Toadstool. In Snow White, Morton and the other Koopalings play a similar role, once again being defeated by Mario as he attacks Bowser's Castle.

Cartoons
In The Adventures of Super Mario Bros. 3 and Super Mario World cartoons he was renamed Big Mouth Koopa Jr. (although the "Jr." part was only mentioned on the bonus disc of The Adventures of Super Mario Bros. 3 DVD set released by Shout! Factory. Thus, he is commonly known simply as Big Mouth Koopa), ostensibly because he was more talk than action. Aptly, in the Super Mario World cartoon, he occasionally served as an announcer.

There are a few physical differences between Morton and Big Mouth: Morton's shell is gray and in the Super Mario Bros. 3 cartoon, Big Mouth's is purple; Big Mouth has much larger eyes and purple eyelids; and the star-shaped birthmark on Morton's face is darker around the cheek, while it's just one solid color on Big Mouth. Sometimes, Big Mouth's name is spelled as Bigmouth. He was voiced by Dan Hennessey.

Mario is Missing!
In this game, Morton travels to Earth to help Bowser steal artifacts from around the world. Bowser intended to sell the artifacts in order to raise funds to buy hairdryers from Hafta Havit Mail-Order, which he would then use to melt Antarctica, thus flooding the Earth.

Morton and most of the other Koopalings guard Bowser's Antarctic fortress and battle Luigi as he searches for Mario and strives to foil Bowser's plot. Luigi easily defeats the Koopaling by stomping on his head repeatedly (or, in the PC version, hit him with a fireball).

Yoshi's Safari
In Yoshi's Safari, Morton helped his family invade Jewelry Land and steal the jewels that maintain the stability in the kingdom. Bowser entrusted one of these jewels to Morton, who then watched over the area known as Spirit Mountain. He attacked in a giant, blue, mechanical frog built by Iggy, but Mario and Yoshi defeated him with the aid of a Super Scope.

Hotel Mario
In Hotel Mario, Morton was given the treetop WoodDoor-Hysteria hotel to run when the Mushroom Kingdom was once again taken over by Bowser. Here, he held Princess Toadstool captive for a short while, but soon became the first Koopaling battled and defeated by the Mario Bros. in this game.

Mario & Luigi: Superstar Saga
Morton and his bros. and sis reappeared in Mario & Luigi: Superstar Saga were they guarded Bowser's Castle, here Morton learned a new attack, sending shockwaves. Despite this new attack Morton ended up being beaten and has once again disappeared.

Super Princess Peach
Some unused sprites of Morton were found in Super Princess Peach which has spread speculation that the Koopalings were going to appear in it.

Personality
Morton's personality and traits have been shrouded in mystery, even more so than compared to his other siblings. Although, according to the Nintendo Player's Guide for Super Mario Advance 4, Morton is a grouch with a cantankerous personality.

In The Adventures of Super Mario Bros. 3, all the Koopalings were given names to match the personalities they were given and such was the case with Morton, whose name was changed to Big Mouth Koopa. Big Mouth was extremely talkative, to the point of never seeming to know when to stop talking, which continuosly forced Roy to interrupt him. However, Morton lacked any speech in most Mario games.

Physical Appearance
Morton Koopa Jr. seems completely unique when compared to all of his other siblings. His skin is brown, his head is white and his shell is black, which are all traits not shared by any other Koopaling. Morton's other trademark features include four fangs, long eyebrows, three curls of hair on the top of his head and a large, grey tattoo on the left side of his face, which is shaped like a star. In size, Morton seems quite obese. He is more bigger than many of his siblings, although he is still smaller than Roy and Ludwig. This contradicts in New Super Mario Bros. Wii, where he has clearly grown larger than ever before, now being the largest in the bunch. His shell isn't also as unique as before, as all of the Koopalings have gained their own unique color for their shells.

Morton stayed relatively same in The Adventures of Super Mario Bros. 3 as Big Mouth. The only noticeable difference was that he wasn't as obese as in the games, thus being rather small.

Bio from The Adventures of Super Mario Bros. 3 Writers Bible
''Big Mouth just can't stop blabbing, and his twisted talent is insult. His cutting remarks can even reduce his father to tears. Big Mouth's got a chip on his shoulder the size of the Doomship. He would never admit he was wrong, even though he usually is. He thinks he knows everything about everything, but what he knows is all wrong, and he always blames the other guy for his mistakes. Big Mouth loves to stir up trouble, and has a needling probing attitude that always gets it. He holds grudges against the whole world.

Name Controversy
Morton is named after Morton Downey Jr.. The editors of the magazine Nintendo Power once claimed that when they asked Bowser why Morton Koopa was called "Jr.", he responded by pelting them with Bob-ombs. It is possible that Morton is adopted, or that "Bowser" is not Bowser's real name. It is also possible that he may be named after Bowser's Father, who is believed to be named Morton. Note that this isn't an issue in the original Japanese continuity, as he is simply named "Morton" and not given a full name.

Quotes
"You're a royal pain!!! And we need you'r cage for our prisoners!!!"
 * "That's Prince Hugo the Huge! The new ruler of Giant Land! They say he's the biggest, toughest, bravest prince ever! Even for a giant, he's a giant." - Sneaky Lying Cheating Giant Ninja Koopas
 * "Yeah, and they're gonna pick you to be their leader! Isn't that always the way? Treat people lousy, dump garbage on their heads and they'll follow you anywhere!" - Recycled Koopa
 * "Have a good time! Have a nice day! Sayonara! So long! Ciao! See you later, alligator! Ciao! Bon voyage! Hasta la vista! Be sure to write!" - Send in the Clown
 * "Let's do an ambush..." - Do the Koopa