“Uh-oh, Baby Luigi time!”
Baby Luigi is the infant form of Luigi. In the Yoshi series, he is kidnapped several times by Baby Bowser and Kamek. In these games, he has been rescued by Baby Mario, with Yoshi. Besides the Yoshi series, he has appeared in several spin-off titles such as the Mario Kart series. He is voiced by Charles Martinet, as with his older self.
 Yoshi series
 Super Mario World 2: Yoshi's Island
Baby Luigi appears with Baby Mario during Super Mario World 2: Yoshi's Island (and its remake Yoshi's Island: Super Mario Advance 3) when he and the Stork carrying him are captured by Kamek. Baby Luigi is then taken to Bowser's Castle. Baby Mario and Yoshi eventually rescues Baby Luigi. The Stork then successfully delivers the Baby Mario Bros. to their parents.
 Yoshi Touch & Go
In the Nintendo DS game, Yoshi Touch & Go, Baby Luigi is kidnapped again by Kamek's Toadies. To rescue Baby Luigi, Yoshi must fling Yoshi Eggs at the Toadies. Also, when players are playing the multiplayer mode, the second player's Yoshi is toting Baby Luigi.
 Yoshi's Island DS
Bowser and Kamek kidnap Baby Luigi, who is one of the kidnapped babies in Yoshi's Island DS. After Baby Mario, Baby Peach, Baby Wario, Baby Donkey Kong, and Baby Bowser team up, they all proceed to rescue him. Bowser and Kamek kidnapped all of the babies because they were searching for the seven Star Children. Baby Luigi hides at the time Bowser and Kamek are checking the toddlers for stars, and, as a result, he never finds out that he is a Star Child himself.
 Mario Kart series
 Mario Kart: Double Dash!!
Baby Luigi makes his playable debut in Mario Kart: Double Dash!!, his weight class being light-weight. Baby Luigi's default partner is Baby Mario and his kart is the Rattle Buggy. Their special item is a Chain Chomp, which can pull them forward at high speeds and knock over any opponent who gets in the way. Baby Mario and Baby Luigi also have a course in this game, which is Baby Park.
 Mario Kart DS
Although Baby Luigi does not appear as a playable character in Mario Kart DS, Baby Park from Mario Kart: Double Dash!! reappears as a Retro Course in the game.
 Mario Kart Arcade GP 2
Baby Mario and Baby Luigi also make a cameo appearance in Mario Kart Arcade GP 2, with several notable characters. They are seen throughout Yoshi Park 1 and have a sponsor, Baby Land, seen in Mario Highway, Mario Beach, Donkey Kong Jungle, and Bananan Ruins.
 Mario Kart Wii
Baby Luigi later returns to the Mario Kart series as an unlockable character in Mario Kart Wii as a small driver, meaning his karts generally have high acceleration, handling, drifting, and Mini-Turbo, but generally lower speed and weight. Baby Luigi's karts are the same as the other light-weight characters, except that his are green and share the same trademark L emblem as Luigi. Unlocking eight Expert Staff Ghost Data in Time Trials, winning 100 WFC Ghost Races, or playing 3,150 races unlocks Baby Luigi. He is tied with Baby Daisy for having the best speed bonus in the game for small drivers, which makes any vehicle have a slightly higher top speed. Baby Luigi also has the biggest bonus, with Baby Mario, which is his weight bonus. It significantly increases the weight of Baby Luigi's kart.
 Super Smash Bros. series
 Super Smash Bros. Melee
 Super Smash Bros. Brawl
 Mario Power Tennis
 Mario Baseball series
 Mario Superstar Baseball
Baby Luigi appears in Mario Superstar Baseball as an unlockable speed character if the player completes Challenge Mode using Yoshi's team, which he just so happens to be on. Baby Luigi is classified as a speed character, which means he excels at stealing bases and fielding. Baby Luigi's special ability is Wall Jump, which enables him to catch any would-be home-runs. However, Baby Luigi's batting and fielding stats are very low and he has average pitching.
 Mario Super Sluggers
Baby Luigi appears in Mario Super Sluggers, where he is available from the start, unlike the preceding game. Baby Luigi has better fielding skills than in Mario Superstar Baseball and his special ability is Super Jump rather than Wall Jump. Super Jump enables Baby Luigi to jump higher than other characters who do not have this ability. The player can recruit him in Challenge Mode by rescuing him in Mario Stadium by turning switches to open up a bridge. As all of the other baby characters in the game, Baby Luigi cannot speak and instead says incomprehensible words that only Lakitu can interpret.
 Mario & Luigi: Partners in Time
Baby Luigi plays a starring role in Mario & Luigi: Partners in Time. Here, he teams up with Mario, Luigi, and Baby Mario to stop the Shroob invasion in the past. He first meets Mario and Luigi after they have been defeated by the Shroobs in Hollijolli Village. Most of the game, he travels piggyback on Luigi but ventures with Baby Mario if the adult brothers throw them. After traveling throughout the past, beating enemies, and acquiring the Cobalt Star Shards, Baby Luigi and the others eventually stop the Shroob invasion. After this has been accomplished, Baby Luigi, with others, return to the past.
In battle, Baby Luigi battles identically to Baby Mario. He does not fight at the very beginning of the game, but is able to later on. His default ability is jumping on foes, which he cannot perform on spiked enemies. Baby Luigi, along Baby Mario, later acquire hammers to injure spiked foes and be able to venture further in the game. For all attacks, he must time the attack for the most damage. If not, Baby Luigi either does a hurt-like pose after a jump, drops the hammer head, or trips and lands on his face when using the hammer if the button is pressed too early. Baby Mario and Baby Luigi also acquire overworld abilities in the game: the Baby Drill, which enables them to dig underground; the Baby Spin, which allows them to reach hard to reach areas that Mario and Luigi can't access, even with the Spin Jump; and the Baby Cakes, which enables them to slip underneath cracks that cannot be accessed by the Baby Drill and float on winds due to compressed weight. He can also use Bros. Items, but he needs a partner to do so. If Luigi faints, Baby Luigi drags Luigi out of battle and fights in his place; if Baby Luigi faints, Baby Mario or Mario carries him, and his added weight hinders dodging capabilities. If Baby Mario faints, Baby Luigi carries him when enemies are attacking, and it also hinders his jumping abilities. Stat wise, he differs from Baby Mario in most ways. Baby Luigi has slightly less speed and less attack, but more HP and defense. However, he has more speed and less HP, defense, attack, and 'stache than his adult counterpart, Luigi.
 Luigi's Mansion: Dark Moon
 Super Mario-Kun
Baby Luigi has made several appearances in the Japan-exclusive manga, Super Mario-Kun. He first appears in Volume 14, which is based on Super Mario World 2: Yoshi's Island. In this comic, the present Mario and Luigi travel to the past to stop Bowser from helping Kamek kidnap Baby Mario and Baby Luigi, and they also aid Yoshi to deliver the Baby Mario Bros. to their parents. As in the game, Kamek ambushes the stork and makes off with Baby Luigi, with Baby Mario dropping with Mario, Luigi, and Yoshi. As Baby Luigi arrives to the castle, Bowser does not appear to take a liking to Baby Luigi, despite Baby Luigi being playful, and ends up biting his head and even giving a spanking after Baby Luigi urinates on him. Later on, Bowser and Kamek torture Baby Luigi, and then Kamek disguises himself as Baby Luigi to throw the three heroes off.
Baby Luigi later appears in Volume 35 and Volume 36, which is based off Mario & Luigi: Partners in Time and Volume 40, which is based off Mario & Luigi: Bowser's Inside Story. Just as in the games, he teams up with the adult Mario Bros. and Baby Mario to stop the Shroob invasion.
 General information
 Physical description
Baby Luigi is very similar to Baby Mario. Both have black, beady eyes and a large, trademark nose. He also has brown hair always covered by his trademark "L" hat. The only major difference between Baby Mario and Baby Luigi is that Baby Mario wears a red shirt and red cap, while he wears a green shirt and green cap. Several minor differences from Baby Mario include his head shape, his eyebrows, his waist, and his sideburns. Also, Baby Luigi's sneakers are green instead of cyan like Baby Mario's.
Baby Luigi, as his adult counterpart, is described as being meek and cowardly. For the most part, Baby Luigi is friendly too, as he gets along well with the other babies. Baby Luigi's timid nature is also evidenced in the Mario Kart Wii official guide, which states that he used to ride with Baby Daisy until her boisterous personality scared him. Games such as Mario Kart Double Dash!! and Mario Superstar Baseball also depict Baby Luigi as a shy person, stating that his appearance in Mario Kart: Double Dash!! is the first time he appears in front of a crowd. Also, when he speaks, he usually sounds uneasy, just as Luigi. Baby Luigi also has an ability to sense danger; in Mario & Luigi: Partners in Time, Baby Luigi seems to be the only one who knows that restoring the Cobalt Star shards would restore the Elder Princess Shroob because he cried when he saw something in the Cobalt Star. He also hides from Bowser and Kamek as they attempt to locate the stars found in the Star Children. Although he is crybaby, as seen in Mario & Luigi: Partners in Time, he seems to actually be less cowardly than his older self.
 Interactions with other characters
 Baby Mario
Baby Mario is Baby Luigi's older twin brother and best friend. Baby Mario, with the guidance of Yoshi, saves him in Super Mario World 2: Yoshi's Island, Yoshi Touch & Go, and Yoshi's Island DS. In Mario & Luigi: Partners in Time, the brothers team up in the beginning of the game to rescue Baby Peach from Baby Bowser. The two have good chemistry in Mario Superstar Baseball and its sequel Mario Super Sluggers. Baby Mario is also Baby Luigi's default partner in Mario Kart: Double Dash!! and the two go with each other to Mario and Luigi's tennis match in Mario Power Tennis.
 Baby Daisy
Baby Luigi's interactions with Baby Daisy mirror the interactions of their adult counterparts. In Mario Kart Wii, there is a statue of the two holding hands and dancing together on the Daisy Circuit course. The official guide for Mario Kart Wii also states that Baby Daisy used to ride with him until he got frightened of her. The two also share chemistry with each other in Mario Super Sluggers.
In all of the instances that Baby Luigi has been kidnapped, Yoshi has been assisting the other babies to rescue him from the beginning of each game. In Super Mario World 2: Yoshi's Island, all of the Yoshis of Yoshi's Island decide to help Baby Mario rescue his brother from the clutches of Kamek. In Yoshi Touch & Go, Yoshi and Baby Mario proceed to rescue Baby Luigi in every level. Finally, in Yoshi's Island DS, Yoshi teams up with Baby Mario, Baby Peach, Baby Donkey Kong, Baby Wario, and Baby Bowser to rescue Baby Luigi from Kamek and Bowser.
 His older self
Although Luigi is very forgetful, such as times when he leaves Baby Luigi behind during Petey Piranha's arrival, he's very caring for Baby Luigi and usually calms him down when he's crying. A scene in Mario & Luigi: Partners in Time involves Luigi about to eat a cookie but he realizes Baby Luigi wants it. He decides to give the cookie to Baby Luigi, and Baby Luigi thanks him afterwards. At the end of the game, Baby Luigi is very reluctant to go back to the past and leave Luigi behind. When Baby Luigi finally decides to give in, he sends his hammer as a gift, but humorously knocks Luigi out instead of simply giving it to him, like Baby Mario does to Mario.
 Star Children
Baby Luigi seems to get along well with other babies. Examples of this are that he shares good chemistry with Baby Peach and Baby Donkey Kong in Mario Super Sluggers. Another example is that Baby Wario and briefly Baby Bowser, team up with the other babies to rescue Baby Luigi in Yoshi's Island DS.
 Official profiles and statistics
 Mario Kart series
 Mario Baseball series
 Bad Chemistry
 Star Missions
 Star Titles
 Names in other languages