Luigi

Luigi (Japanese: ルイージ, Ruīji) is Mario's younger, taller, thinner twin brother. He is a major protagonist of the Mario series. Luigi has helped and fought alongside his brother on many occasions. Throughout his life, he has lived in Mario's shadow, developing both cowardly and heroic tendencies. Mario Bros. marks his first appearance in the Mario series and his debut in general. Originally a palette swap of Mario, Luigi was created to facilitate a second player option. Since the two-player mode was dropped from most main Super Mario games beginning with Super Mario Land, Luigi has gained his own identity and personality. This is especially noticeable in installments for the Luigi's Mansion series of games, as well as the Mario & Luigi series.

Family
Luigi often accompanies his older twin brother Mario on his adventures, most prominently in the Mario & Luigi series. While there is some sibling rivalry between the two, with Luigi sometimes feeling jealous and overshadowed by his brother, he also admires and looks up to him, wishing to be "a great plumber like his brother Mario" in Super Mario RPG. The two share a loving brotherly bond so strong that as babies, Baby Mario could sense where his brother was after they were separated by the Koopas. This closeness continues into adulthood, with the brothers frequently coming to each other's aid and rescue. While Mario is generally the more heroic and active of the two, Luigi has saved him on a few occasions, starting with Mario is Missing! and subsequently in Luigi's Mansion, and its sequel, Dark Moon, wherein Mario calls Luigi "number one" upon his rescue.

Friends
One of Luigi's closest friends is Yoshi, and the two are often referred to as "The Green Team" when partnered up in spin-offs, although in he Mario Baseball series their chemistry is only neutral. Their relationship is much closer in the Super Mario World TV Show, which depicted Yoshi as having originally thought Luigi was his mother and still enjoys hearing him tell him bedtime stories, as seen in the episode Mama Luigi. He is also good friends with Toad, although they are not quite as close as Toad is with Mario, and while other Toads are almost unanimous in their praise and adoration of Mario, their opinions on Luigi vary greatly between individuals. Some are unabashed fans of Luigi, with one in Super Mario 64 even asserting that "We'll have to call you the Luigi Brothers soon!", while others are disbelieving that Luigi should measure up to Mario, with one going so far as to call him "The world's most inept and least charismatic brother". Similarly, Luigi's relationship with Starlow is far less cordial than she is with Mario, with her often belittling and mistreating him, but at the same time acknowledging that despite not being as great as Mario, he is still a hero.

Princess Peach is another one of Luigi's good friends, with him often accompanying Mario on quests to rescue her from Bowser, the two sharing good chemistry in the Baseball games, and overall friendly behaviour seen between them, occasionally overlapping with hints of romantic attraction as well. Luigi is seen swooning over Peach after she blows a kiss in her Mario Power Tennis victory scene, and in games where Luigi can be substituted for his brother, her interactions with him are the same as they would be with Mario, such as rewarding him with a kiss at the end of most Super Mario platformers, or even being referred to as "special one" by Rosalina in Super Mario Galaxy. Overall, however, the two are portrayed as simple friends, with Daisy serving as Luigi's main love interest, although he has also expressed interest in the unseen Princess Eclair of the Waffle Kingdom. He has also been speculated to have an interest in Rosalina owing to the fact that he and Rosalina are photographed together just as Peach and Mario were pictured together in the image sent by the Mailtoad in Grand Finale Galaxy, and to the fact that he only gives Mario the Green Stars he collected in Battlerock Galaxy if Mario tells Rosalina they're from Luigi.

It has been stated that Luigi has a crush on Daisy, and the attraction appears to be mutual. In Daisy's second appearance in the Mario series, NES Open Tournament Golf, she served as Luigi's caddy, just as Peach was caddying for Mario, and as her trophy in Super Smash Bros. Melee points out, since that point "some gossips started portraying her as Luigi's answer to Mario's Peach". They are often paired up in spin-off games: they are seen golfing together in Mario Golf Toadstool Tour, are "buddy players" with good chemistry in the Mario Baseball series, they appear together in the Miracle Book pages from Mario Party 6, and in Mario Kart Wii, there is a giant, golden statue on the Daisy Circuit that shows the two holding hands and dancing together, along with another of Baby Luigi and Baby Daisy. Their team names from the Mario Party series include, "Steady Sweeties" and "Tango Tanglers", and when Daisy received her trophy from Luigi in Mario Power Tennis, she says, "Hey, sweetie! I'll take that".

Another one of Luigi's friendships can also be seen with Professor E. Gadd. Although the only interactions between the 2 were in the Luigi's Mansion series, they worked very well together. E. Gadd shows much trust in Luigi, despite Luigi's cowardly nature. Throughout Luigi's Mansion: Dark Moon, E. Gadd jokingly held Luigi in low regards, though he also states to be proud of him for courageously exploring the hostile ghost filled mansions as well as defeating the various possessor ghosts.

Enemies
Bowser's main rivalry is with Mario, and while he views Luigi as almost a great a threat as his brother in games such as Super Mario Galaxy and its sequel, at other times, Bowser has trouble even remembering Luigi's name, particularly in the Mario & Luigi where he often defaults to calling him "Green 'Stache" (Although Bowser finally calls Luigi by his real name at the end of Mario & Luigi: Dream Team). Rather than Bowser, Luigi's arch-nemesis is actually King Boo, who he met and defeated single-handedly in Luigi's Mansion when the ghost kidnapped Mario. King Boo would later try to get revenge in Luigi's Mansion: Dark Moon, and the rivalry can be seen in other series as well, such as the Mario Baseball games, in which they share bad chemistry, or Super Mario 64 DS, where King Boo (Known as Big Boo in the English version) was the one to lock Luigi away.

Another heated rivalry exists between Luigi and Waluigi, with the two sharing bad chemistry in all the games they appear in together, and acting hostile and rude towards each other, such as Luigi making a gesture at Waluigi to anger him in Mario Tennis, the two scowling at each other in the Mario Party 3 group picture, and Waluigi´s vandalism of Luigi´s picture in the opening movie of Mario Power Tennis. Waluigi is constantly seen harassing Luigi, wether by humiliating him during the sports competition, following him wherever he goes or even directly confronting him. The origins of their animosity are unknown, however jealousy may be a factor, as both Luigi and Waluigi have crushes on Princess Daisy. Luigi himself, while he despises Waluigi, prefers to ignore him and his antics

Just as Luigi's relationships with Daisy and King Boo mirror Mario's relationships with Peach and Bowser, respectively, so too does Luigi's rivalry parallel the one between Mario and Wario. Wario himself does not show as much antagonist towards Luigi as his brother, although the two do not get along well and it has been shown that Wario enjoys giving Luigi trouble, such as by tying his shoelaces together.

Nicknames

 * The Luigi Kid - The Super Mario Bros. Super Show!
 * Long John Spaghetti (by Mario) - The Super Mario Bros. Super Show!
 * Mama Luigi (by Yoshi, and later himself) - Super Mario World television series
 * Weegee (by Mario) - Super Mario Adventures
 * Plunger Puss (by Larry Koopa) - Mario is Missing!
 * Plumber Dude (by Larry Koopa) - Mario is Missing!
 * The Eternal Understudy - Super Smash Bros.
 * Master Luigi (by Toadsworth) - Mario & Luigi: Superstar Saga
 * Mr. Green (by Bowser) - Mario & Luigi: Superstar Saga
 * Green Guy - Mario & Luigi: Superstar Saga, Super Princess Peach
 * Mr. Green Mario Brother Guy (by Bowser) - Mario & Luigi: Superstar Saga
 * Green man of mustache (by the star gate) - Mario & Luigi: Partners in Time
 * Green 'stache (by Bowser) - Mario & Luigi: Superstar Saga, Mario & Luigi: Partners in Time, Mario & Luigi: *Bowser's Inside Story, and Mario & Luigi: Dream Team (also called by a Whittle in Super Mario Galaxy 2)
 * Mr. Lean 'n' Green - Mario & Luigi: Superstar Saga
 * Mr. Greenie - Mario & Luigi: Superstar Saga
 * What's-yer-name (by Bowser) - Mario & Luigi: Superstar Saga
 * The Other Guy - Mario & Luigi: Superstar Saga
 * Lip Hair (by Baby Bowser) - Mario & Luigi: Partners in Time
 * Shabby green mustachioed man (by Princess Lipid) - Mario & Luigi: Bowser's Inside Story
 * Man in Green (by Dark Prognosticus) - Super Paper Mario (also known as the "man in green" in Super Smash Bros. Melee in the notice after unlocking Luigi)
 * Mr. Lime-Green - Luigi's Mansion
 * The Mustachioed Green Baron - Paper Mario: The Thousand-Year Door
 * Mr. Eyeballs (by Waluigi) - Mario Power Tennis
 * Mushroom Dynamite - Mario Hoops 3-on-3 baller name
 * Sweetie (by Daisy) - Mario Power Tennis
 * King of Second Bananas (by Colonel) - Super Smash Bros. Brawl
 * Green Wimp (by Bowser) - Mario & Luigi: Partners in Time
 * The Green Thunder (as Mr. L) - Super Paper Mario
 * The Great Dweeb (by a Goomba) - Super Paper Mario
 * Green Wonder - Super Smash Bros. Brawl
 * Everyone's favorite man in green (by Masahiro Sakurai) - Super Smash Bros. Brawl website (Smash Bros. DOJO!!)
 * Air Luigi (by Koopa Koot) - Paper Mario
 * Mysterious Green Guy - Paper Mario: Sticker Star