Green Fireball

A Green Fireball is an obstacle and also Luigi's trademark element in most spin-off games. Sometimes functioning identical to Mario's Fireballs.

Other elements Luigi can use, however, include electricity as seen in Mario & Luigi: Superstar Saga and Mario Strikers Charged, whirlwinds as seen in Mario Super Sluggers, and Ice Balls as seen in Mario Kart Arcade GP DX for Ice Luigi and as a customization move for Luigi in Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U.

Mario Bros.
Green Fireballs first appear as obstacles in Mario Bros., The green fireballs move horizontally from one side of the screen to the other where it will disappear until respawning elsewhere. It has a pattern of two small wavy bounces and one long bounce. Typically, the green fireballs spawn on a row where a player is located. To destroy green fireballs, the player has to bump them from below while they are touching the platform, or use a POW Block. Only two green fireballs can spawn on the screen at once.

In the Atari 2600, Atari 5200, Amstrad CPC, and other ports of Mario Bros., the green types are absent.

In the NES port of the game, green fireballs are significantly smaller, making them easier to avoid.

In the Super Mario All-Stars version of the Battle mode, the green fireballs are replaced with Boos, though both types appear red in the 2 player mode.

Super Mario World television series
A Green Fireball appears in the Super Mario World television series episode "The Wheel Thing", representing the green-light signal in the fire traffic lights. When Mega Mechanasaur passes the traffic lights without stopping from the lit-up red fireball, the green fireball along with the red and yellow ones get shot out towards Mega Mechanasaur, breaking off its arms.

Super Smash Bros.
Green Fireballs first appears as Luigi's element in Super Smash Bros. as Luigi's standard special move. The move is called Fireball, the same name as Mario's move, but it floats while drifting around in a circle, rather than bounces. Kirby can use Green Fireballs if he copies Luigi's ability.

Super Smash Bros. Melee
Green Fireballs reappear as Luigi's standard special move and when Kirby copies his ability in Super Smash Bros. Melee. Metal Luigi can also uses Green Fireballs during his boss fight alongside Metal Mario.

Super Smash Bros. Brawl
Green Fireballs reappears as Luigi's standard special move and when Kirby copies his ability in Super Smash Bros. Brawl. The Mario Bros. stage also features only the green fireballs, bouncing around the stage and damaging any non-protected fighters they come in contact with, while being burnt. False Luigi in The Great Maze can also shoot green fireballs.

Super Smash Bros. for Nintendo 3DS / Wii U
Green Fireballs return once again as Luigi's standard special move and when Kirby copies his ability in Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U. The Green Fireballs can be altered into either Bouncing Fireball or Ice Ball via custom moves, provided that they are unlocked first. Bouncing Fireball is affected by gravity with each successive bounce decaying in height, much like Mario's Fireball, although Luigi takes more time to fire it. In comparison, Ice Ball has a chance of freezing opponents and has longer range, but deals slightly less damage and travels slower. As Master Shadow can copy characters and their abilities, he can also copy Luigi to shoot green fireballs as well.

When Kirby copies Luigi, he will always remains with Luigi's default standard special, even if Luigi has a set custom move.

Super Smash Bros. Ultimate
Green Fireballs return once more as Luigi's standard special move and when Kirby copies his ability in Super Smash Bros. Ultimate. As the Mario Bros. stage returns, the green fireballs reappear as obstacles once again function the same way like in Super Smash Bros. Brawl. Dharkon's False Luigi can also shoot green fireballs.

Mario Kart: Double Dash!!
Green Fireballs appear in Mario Kart: Double Dash!!, as Luigi's Special item and can be used only by him; not even Petey Piranha or King Boo can use it. It works similarly as Mario's Fireball item. When Luigi throws it either forward or backward, the green fireball splits into five and bounces around the course, which may ricochet off walls. The fireballs, when they hit any kart, including Luigi and his teammate's kart, cause the kart to spin out and the rear player is burned and momentarily stunned. They are one of the only two Special Items that cannot be obtained by King Boo or Petey Piranha, the other being the Birdo's Egg. If a green fireball hits a heart, the icon for the green fireball received is a red fireball.

As well as having the special item, Luigi has a personal kart, the Green Fire, unlocked once players beat Mushroom Cup on 50cc.

Paper Mario: The Thousand Year Door
Undead green fireballs known as Phantom Embers, appear as enemies in Paper Mario: The Thousand Year Door. They can also spit green fireballs that hit either Mario or his partners, which causes five attack points and they can sometimes set Mario (or his partner) on fire.

Mario Power Tennis
Green Fireballs based on their Mario Bros. sprite appears in Mario Power Tennis, they appear as obstacles in the mini-game Coin Collectors, they bounce around the court and must be avoided. When the player goes in contact with one, it KO's player for three seconds (along with the classic defeated sound effect playing).

Mario Superstar Baseball
The Green Fireball, again simply known as the Fireball, is Luigi's Star Skill in Mario Superstar Baseball. When pitched with, the Green Fireball surrounds the ball with green fire and throws it as a fastball with very high velocity and little movement. Compared to Mario's equivalent Fireball pitch, it has slightly lower velocity and greater movement, matching Luigi's specialties as a pitcher. When batted with, the Green Fireball also surrounds the ball with green fire, hitting it as a ground ball to the infield. Players who attempt to catch the ball while it is lit are burned, stunning them for a short time.

In Challenge Mode with Mario, the player must purchase the Green Fireball item in order to enable use of this ability for Luigi.

Mario Hoops 3-on-3
A Green Fireball is used in Mario Hoops 3-on-3, as Luigi's Special Shot known as the Green Fire Shot, identical to Mario's Fire Shot. When the player taps out the letter L on the touch screen, Luigi starts charging the ball with green fire. If he is not hit while charging it, he launches the ball to the basket. It always scores if it is shot inside the 3-Point line. When shot outside the 3-Point line, a teammate must complete the move, and it is not guaranteed the shot scores. It functions exactly like Mario's Fire Shot dunk however, Luigi's fire is green and he, of course, dribbles out an "L" instead of an "M".

New Super Mario Bros. Wii
Green Fireballs make their Super Mario series debut in New Super Mario Bros. Wii. In World 5-Tower, Iggy Koopa shoots Green Fireballs from his magic wand to attack Mario and co. The speed of these fireballs are the fastest in the game, along with Morton's.

When Mario and co. encounter Iggy again in the World 5-Castle, he still shoots Green Fireballs from his magic wand, although not as fast as in his first battle.

New Super Mario Bros. 2
Green Fireballs reappear in New Super Mario Bros. 2, where Iggy's magic wand once again shoots Green Fireballs, much like in New Super Mario Bros. Wii.

New Super Mario Bros. U / New Super Luigi U / New Super Mario Bros. U Deluxe
Green Fireballs once again return in New Super Mario Bros. U, New Super Luigi U, and their Nintendo Switch ports. This time, Iggy waves his wand and shoots three fireballs while standing on the ceiling, some being his usual green flames, and some instead being red orbs that generate Magmaarghs when they land into the lava below.

Super Mario 3D World
Green Fireballs appear in Luigi Bros., an additional game featured in Super Mario 3D World. Like the other enemies and obstacles in Luigi Bros., green fireballs behave in the same way as Mario Bros., which this game is based on.

WarioWare: D.I.Y. Showcase
Green fireballs appear as a recolored fireball sprite from Super Mario Bros. in WarioWare: D.I.Y. Showcase, it appears in 18-Volt's boss microgame Dustpan, as an obstacle that roams on the stage and must be avoided.

NES Remix / NES Remix Pack / Ultimate NES Remix
In NES Remix and it's compilation re-releases, When playing the Mario Bros stage 9-1. The player must defeat the green fireball by bumping it from below while they are touching the platform. Stage 9-3 has the player to defeat both red and green fireballs in the same method to defeating them like in the original game. Green fireballs can also appear as obstacles in different challenges.

Mario Sports Superstars
A Green Fireball appears in Mario Sports Superstars, as Luigi's special shot in baseball and soccer. When using his special shot, the ball is encased in a Green Fireball. Baby Luigi also uses a Green Fireball in his special shot in soccer only. In baseball, players who attempt to catch the ball in while it is lit are burned, stunning them for a short time.

Trivia

 * Due to palette limitations in the NES version of Super Mario Bros. 3, Fire Mario and Fire Luigi's fireballs appear green inside Toad Houses.
 * Despite Luigi's fireballs being green in the Super Smash Bros series, they still make red-orange burn animations upon impact on a character.