Dragon Ball Z movie villain Broly, aka the Legendary Super Saiyan, is the only character to have a consistently green aura. This may have been an effect of his father's mind control device, but afterwards he still has a green tint to his hair and aura and all his special attacks are green. Finally, his imperfect clone "Bio-Broly" degenerates into a green blob monster.
Sesshoumaru from InuYasha, when he uses his Toxic Flower Claw or any variation of it. In fact, the first time you see the Aristocratic Assassin, he uses it against a ferocious pack of wolves, and eviscerates them with ease.
The Loud G-Stone used by the Sol 11 Masters in GaoGaiGar FINAL glowed the same color as the normal G-Stone, but displayed an upside-down G symbol when active. But then, real power in GGG was orange (THE POWER, Genesic Aura), though it was always the G-Stone that did the job in the end, thanks to its theoretically infinite energy output.
Quantonium, the mysterious substance that sets the events of Monsters vs. Aliens in motion, glows sickly green. After Susan is exposed to it (read: hit by a meteor full of the stuff), she too glows green when she starts growing.
The thalaron beam in Star Trek: Nemesis is green, and the final battle takes place in the Bassen Rift, which is a nebula with a very sickly green glow.
In Alien: The movie poster shows a cracked egg with a green light shining inside.
In Creepshow, Ted Danson's character acquires a green glow as the tide covers his head. "I can hold my breath for a long time!"
In 1987's The Curse, an adaptation of H.P. Lovecraft's "The Colour Out of Space", the colour turns out to be green. Of course, in the story, the color was something never seen on Earth before. Any special effects team that can really produce that probably HAS cut a deal with the Great Old Ones.
All the scenes taking place in the Slytherin dorms in the Harry Potter movies. Someone went crazy with green light. In this case, though, there's a valid reason: in the second to last novel, the Slytherin dorms are explicitly said to be green-lit due to the windows being below the lake's waterline.
The outer glow around the Hobgoblins titles is green. Take warning.
The titular artifact of The Mask sometimes emits a green glow.
By the end of Repo Man, the aliens in the trunk convey a bright green glow to the Chevy Malibu.
Invoking this, the Viper from The Wolverine is known as Dr. Green and wears green as she's a Poisonous Person (the version from the comics, Madame Hydra, also wore that, though the poison was only in her weapons).
The Illearth Stone in The Chronicles of Thomas Covenant, though there's at least one example of a "good" green glow as well - explicitly stated as being of a different, more natural shade.
The Killing Curse in Harry Potter fits the bill, as well as a particularly nasty potion that also has strong ties to the Big Bad.
The Boundaries in The Sword of Truth series, being gateways into the underworld, are naturally bright green.
In Gone , by Michael Grant, this trope is both played straight and averted: The radioactivity in the underwater cave is bright green, while the nuclear reactor is bright blue.
In The Green Futures of Tycho by William Sleator, the main character (11 year old Tycho) travels repeatedly in time, constantly altering the primary timeline. The time travel device (an egg-shaped object) becomes more green-glowing as he uses it, as does the future. First just in the color of the house paint, later there's green liquid-like shapes as furniture or structural additions to the house, glowing sickly green. The older versions of the main character gets more evil (and evil looking) as the "greenage" increases thus closely adhering to this trope.
In the Warrior Cats series, the Dark Forest (which is basically a feline Hell) is described as being completely dark except for a sickly green light.
Titus Groan, the first Gormenghast novel, features Swelter the chef sharpening his cleaver in preparation to murder Flay in a room lit by a green lantern. Even the title of the chapter is "In Lime-Green Light".
The Lord of the Rings: The Barrow-Wights. The Dead Marshes. Minas Morgul. In short, anything associated with the undead.
Shoggoths in H.P. Lovecraft's At the Mountains of Madness are described as enormous black masses of protoplasmic bubbles covered in luminescent green eyes that are constantly forming, shifting around and dissolving.
Also from TNG, both Klingon and Romulan ships and weapons are coloured green. Subverted in the case of the Klingons, who are the Federation's allies. Subverted again with the Romulans in Deep Space Nine when they join the Alliance.
In Star Trek: The Original Series episode "The Galileo Seven", the Murasaki 312 object is a glowing green cloud, in both the original and the new special effects.
Jasmine of Angel glowed green when she ate people.
Because it's just not a trope without a Doctor Who reference; nine out of 10 classic series monsters, at least, were green. This was even referenced by former script-editor / writer Terrance Dicks in a documentary about the show; "The colour of monsters is always gween!"
Don't forget the classic story, The Green Death, which was perhaps the epitome of this trope.
The Family of Blood has a green glow to their ship as well as their faces when they communicate with one other.
The Discontinuity Guide's entry on "Logopolis" lists "Entropy is green" as one of that story's goofs.
In The Doctor's Wife, House manifests itself as a cloud of green smoke when outside its "body". When it possesses an Ood, its eyes glow green (rather than red, which is what usually happens when Ood get possessed). Once it gets inside the TARDIS, the usual lighting scheme is replaced with a suitably ominous green one.
The Battlestar Galactica'' episodes "Torn" and "A Measure of Salvation" feature a Cylon Baseship (which is bio-mechanical) infected by a virus. As the ship slowly dies, the computer panels and other sources of light on the ship give out an eerie green glow. Moreover, the "fleshy" bits of the ship, which normally have a healthy red coloration, take a rotten, dark-green appearance.
Dr. Clayton Forrester from MST 3 K is perpetually outfitted in the absolute brightest greens possible, to denote his mad scientist nature.
The green kryptonite in Smallville, well, at least when Clark comes near it. Usage of some kryptonite-induced powers also glow like this.
In Hercules in the Underworld, the entrance to the realm of Hades is a large hole that emits a column of green light, from which little green ghosts ascend.
Parodied in BritishDom ComOne Foot in the Grave. Victor Meldrew takes delivery of a large consignment of horse manure which is dumped at the end of his drive so in order to stop people walking into it, he places fairy lights on top. When the public finds out that the manure was taken from a farm near a nuclear power plant, they immediately panic and think it's dangerously radioactive.
Mythology and Religion
Though not glowing, Death's horse in The Book of Revelation is called "Khloros", which can be translated as "Pale", "Sickly green", "Yellow green", and so on.
We get the word "chlorine" from the same place - quite fitting, as chlorine does look sickly green.
This is one of the primary color schemes in Big Bang Bar. Somewhat justified in that it's taking place inside a wild alien nightclub.
This is a running theme for the Yozi Malfeas in Exalted. His central soul Ligier is the Green Sun, illuminating his hellish landscape. A considerable number of Malfeas's powers also manifest a green glow of some form, and any Infernal Exalt who opts to learn Malfeas's powers can join the fun.
The "Green Sun Wasting" disease (caused by Malfeas's powers) is basically radiation poisoning.
The Cryx in Iron Kingdoms are renowned for the sickly green emanations of their jacks' necrotite-fueled engines and their tendency to stalk swampy areas, to the point where the livings of Immoren call even mere will-o'-the-wisps "Cryxlights".
Occasionally played straight with those suffering from the Shadowlands Taint in Legend of the Five Rings, but more frequently inverted, as blessed green jade is pretty much the only reliable way to protect both one's soul from spiritual corruption and one's body from physical harm when dealing with the Shadowlands. It also gives off an apparently radioactive glow. This◊, for instance, is a chief holy priest of the good guys.
In the modern version of the Arkham Horror board game, the Color Out of Space, which in the original story was a color never seen on Earth, is pictured as a glowing green.
The black-mana regions of Mirrodin in Magic: The Gathering are covered in eerily glowing necrogen gas, and that's only gotten more pronounced with the Phyrexian takeover.
Antidermis in BIONICLE's story. For the toys, there are the figures that come with glow-in-the-dark pieces — Nocturn, Takadox, Morak, Gadunka, the Piraka teeth, the thingamajig in Roodaka's mouth, and the 2004 collectible disks. Also the Visorak Minifigs and the special Rhotuka spinner from the 2005 playsets.
Which was Averted with Mists Of Pandaria, which adds a Harder Than Hard (at the time of release, at least) quest chain that turns all warlock fire spells green as a sign of prestige among the class.
Similarly, the Scourge used to have the same glow as demons when they were still servants of the Burning Legion. After they became independent, they adopted a new blue white scheme. The color of their embalming ichor remains unchanged however.
Also, the plague created by the Forsaken is green (the Scourge one is mostly orange, though they continue to use green glow at times).
Tron 2.0. Anything "corrupted" in the virtual world glows a sickly greenish-yellow.
The background nebulae in Freelancer have all a dominant color depending on where you are. Liberty's backgrounds are orange and dark blue, Bretonia's are purple and orange, Kusari's are turquoise, Rheinland's are orange with a little bit of green, while the Border Worlds' usually incorporate some white. The Edge Worlds, meanwhile, are barren, crime-ridden places where you get to fight the real enemy; coincidentally, all of them have gas clouds and backgrounds colored sickly green.
Radiation from nuclear strikes in DEFCON glows green, though you change the colour if you wish.
Radioactive material in Half-Life is florescent green liquid.
Fallout 3 has a side-mission where an atom worshiping cult is tainting water with radiation. There are multiple ways to solve the problem, but the easiest involves convincing the cult that you're the avatar of their god and that you want them to stop tainting the water. Since the avatar is said to have a bright glow, you need to get said glow, which involves getting over 800 rads (1000 is the lethal level).
Another side-mission has a character ask you to get radiation poisoning so she can study it's effects for a survival guide she's writing. The optional objective is to get critical poisoning (600), which will cause her to mention that you're actually glowing (and get you a perk... which may possibly come in the form of a benign tumor).
The series also has a form of ghoul called a Glowing One. They generally tend to be hostile, save for JasonBright of Fallout: New Vegas.
If you nuke Megaton, the surrounding area is covered in a sickly green fog. The same thing is seen in Camp Searchlight and other irradiated locations in Fallout: New Vegas.
In Homestuck, energy with a Sickly Green Glow is associated with the powers of the First Guardians and their energy source, the Green Sun. While First Guardians are not necessarily inherently evil, there is apparently a high tendency for them to be spawned as agents in the service of Lord English, facilitating his eventual emergence into and subsequent destruction of their universe. Currently, five known entities have/had the powers and accordingly the Sickly Green Glow - Becquerel, Doc Scratch, Jack Noir, Jade Harley, and the Peregrine Mendicant; however, of the five only Scratch and Jack are evil, andhow.
In the Futurama episode, "The Honking", the headlights and grill of SATAN, the original were-car, emit green rays when he awakes.
Almost subverted in Danny Phantom, where the hero often glows green due to his ghostly powers (and gets 'glowing green eyes' according to the show's opening). However, so do all the other ghosts, who also tend to have green skin or other attributes (and also tend to be evil).
Spongebob: I dunno, Squidward. That ship has a spooky green glow around it.
Same series, one of Mermaid Man's nemesis the Atomic Flounder can apparently shoot out a green beam while howling.
The Batman Beyond villain Blight, appears as a black skeleton wrapped in translucent, glowing green flesh.
Izzy gets one after jumping in a box marked 'radioactive' in Total Drama Island. She then complains to Noah that there wasn't a radio in the box at all.
Princess Cadence from My Little Pony: Friendship Is Magic is shown to have a magical aura that is best described as "radioactive green". The flashback that shows her actual aura is light blue rings the bell that something is definitely wrong; in truth, the green aura is that of the changeling Queen Chrysalis, who's kidnapped and replaced the real Cadence.
Yuck from Yin Yang Yo has this color to his magic. Considering that he doesn't bathe and has a similar color to his fur could tie into the gross factor and his evilness.
The Lich from Adventure Time has this going for him. He's the spirit of an Atomic Bomb.
Mr. Yuk, a warning label applied to poisonous materials, is always colored sickly green; appropriate, considering that he's designed to warn children away.
Green was also considered the official color of evil during the Middle Ages, because it's the color of decay.
There was only one company where workers painting the Radium dials developed said condition, as was they were the only corporation cruel enough to encourage their workers to shape the brush with their mouths. All other Radium painting corps provided special cups for shaping the brushes.
Many old monochrome monitors displayed green-on-black text. You can guess where that led.
Heavily irradiated glass happens to glow this color.
There is a sort of colored glass, named "uranium glass" because it is tinted with uranium salts, which was extremely popular in the beginning of the 20th century. This was the primary use of uranium before its role in nuclear applications became more prominent (uranium's existence was posited in 1789, and pure uranium was isolated in 1841; uranium minerals were well known in antiquity); ceramic glazes and glass containing small amounts of uranium oxide as a coloring agent have been found in Roman ruins dating back to the first century CE. It can be yellow to green or even blue, depending on the actual tinting composition, and is often smoky or opaque, but invariably glows neon green under UV light, including direct sunlight.