"The halo is a purely optical illusion, produced by moisture in the air, in the manner of a rainbow; but the aureola is conferred as a sign of superior sanctity, in the same way as a bishop's mitre, or the Pope's tiara. In the painting of the Nativity, by Szedgkin, a pious artist of Pesth, not only do the Virgin and the Child wear the nimbus, but an ass nibbling hay from the sacred manger is similarly decorated and, to his lasting honor be it said, appears to bear his unaccustomed dignity with a truly saintly grace."
Dead characters in Dragon Ball Z tend to wear halos when in the afterlife, or if they, like Goku of the Majin Buu saga, return to Earth without being resurrected by the Dragon Balls. Turned to "orbs" for some reason in an English dub.
The halos in Haibane Renmei appear to be artificial, created by a blacksmith, and need to be held on by a device until they "stick" and hover over the Haibane's head.
Only in Rakka's case. According to the flashbacks, on most Haibane it normally sticks right away. Incidentally, it's created by putting substance called "light leaves" in a ring-shaped frying pan, and heating it over an oven until it melts and takes uniform shape. No special training is required, but only the Renmei know where the raw material comes from.
At one point in FLCL, Haruko briefly affixes a fake halo made of wire to her head. They later reappear on Canti.
In the Director's Cut and Platinum version (as well as in the manga) of Neon Genesis Evangelion when possessed by Armisael (which starts off as what looks like a giant halo, making this a double pointer), Unit 00 is shown growing a fleshy tumorous mass along its back which incorporates the shapes of almost all the previous Angels they have battled. Then, for a moment the Eva raises in the air and turns into an all white, naked, Rei, that appeared to resemble Lilith, with a halo over her head just prior to exploding.
In the Rebuild of Evangelion, some of the Angels form a halo-like ring around themselves when they use their AT-field for specific actions, such as floating.
Rebuilds 1.11 and 2.22 give all the Angels a halo at some point or another. Sometimes it's only visible for a second, on at least one occasion it actually served a practical purpose beyond simply looking cool, but it always looked quite creepy. Rebuild 3.0 continues the trend: whenever something has a halo, it can fly under its own power and houses immense power. Examples include Unit 01 sprouting a halo during its "fight" against Zeruel and expanding it into a vortex that the third film reveals to have been Third Impact, the Wunder briefly manifesting a concentric pair of halos beneath the ship when it first takes off, the Mark.06 flickering a faint halo just before Rei decapitates it, the SEELE-controlled Mark.09 having a single halo for flight and finally Unit 13 growing a double halo when it enters the same state Unit 01 was in, then the same Eva manifesting a third halo that expands into the same vortex Unit 01 had, except much bigger. Whew!
Based on previous appearances, the "halo" is the manifestation of the Angel's ultimate power: An energy-condensation field, spinning all matter in its wake into pure energy. If the halo belongs to an Eva and the Eva's pilot loses emotionalself-control, the halo turns into theDoor ofGuf that can wipe out all other life within its range or, if given enough time to expand, the entire world.
The angels in Bludgeoning Angel Dokurochan have halos that are only atoms wide and thus, very sharp. Like, "slice off all your fingers upon grabbing," sharp. Additionally, removing the halo causes... stomach issues.
Parodied in Urusei Yatsura. When trickster monk Cherry dispenses a nugget of pop wisdom, everyone is awed and looks in reverence at the shining halo around him, thinking him a saint despite his past. Then Ataru points out in outrage that it's just the light reflecting off Cherry's bald skull.
From A Certain Magical Index, Most of the angel-type characters(like Hyoka, Gabriel and Aiwass) and espers that have reached Angel-level (like Accelerator and Kakine).
Even Gundam is not immune: the Zanscare Empire in Victory Gundam uses a halo motif on several of its superweapons near the end, particularly the Zanneck mobile suit and the Angel Halo satellite weapon. Of course, it's a subversion of the general symbolism, as Zanscare are not particularly nice people.
Apollo, The Cape of The Authority, has one of these. Justified by his solar powers: the halo gets dimmer when he's weaker, and glows brightest when he's just had a good bask in the sun. Or, to put it another way: that's not a halo; that's lens flare.
In silent film Civilization, Count Ferdinand develops an actual halo while talking to the king and his advisors. Why? Because Ferdinand has literally been possessed by Jesus, who has come back to earth to preach that war is evil and wrong.
Lampshaded in The Hudsucker Proxy, as the late Mr. Hudsucker points out his halo (aptly spinning in the style of a hula hoop) and calls it a "fad" with the boys upstairs.
Parodied in Mel Brooks' History of the World Part I. Leonardo da Vinci shows up at the Last Supper to paint his portrait of Jesus and the disciples; the halo behind Jesus's head is revealed to actually be a large platter that a waiter happened to be holding up at the moment da Vinci asked everyone to hold their pose.
Inverted and played for laughs in Bedazzled (2000) when Elizabeth Hurley's Devil tries on different outfits. She ends up looking like an angel, complete with wings and halo but is quick to point out that it's "just a Halloween costume."
In Sixth Column, the Scam Religion set up by the protagonists to fool the PanAsian occupiers includes a full set of priestly garb, complete with staff. The staff is a very sophisticated piece of Applied Phlebotinum which includes among its minor powers the ability to project a holographic halo over the priest's head.
In the Dresden Files book Changeswhen Karrin Murphy draws a holy sword to fight powerful, ancient vampires, Harry releases his spirit friend Bob to protect Murphy from the mental assaults by said vampires. Bob whirls around Murphy's head with a golden radiance, giving her the appearance of a halo.
In the Twilight Zone's A Passage For Trumpet, when John Anderson pauses in the dark hallway to identify himself to Jack Klugman as "Gabe" (short for Gabriel, of course), the sole light in the hallway is directly over his head, forming a perfect halo. Clever effect!
The angels of Touched by an Angel, when revealing themselves to humans, simply maintained the same basic appearance they'd had throughout the episode but were bathed in a golden glow.
The Angels in Supernatural are confirmed to have them in season 8 when a Nephilim says she can see them, but like their wings they are invisible when they're in their human hosts on Earth.
Mythology and Religion
The Trope Codifier seems to be the Christian art canon, where any holy person or being tended to be drawn with a halo.Christian paintings from late Antiquity on often have halos around Jesus/Virgin Mary/Holy Figure of Choice's head. An early distinction was to show living people with square haloes◊, and the sanctified dead with round ones. More than a few paintings of God give Him a triangular, rather than circular, halo, to represent the Holy Trinity. Christ is distinguished by a halo encircling a cross. The almond shaped mandorla sometimes surrounds the entire body of God or the Virgin Mary. The early Renaissance made a distinction between the full round halo given to saints, and rays of light given to beati. In the High Renaissance, the fascination with perspective encouraged artists to create the hoop-shaped haloes that assumed a distressing materiality in later artists, and led to the "halo on a stick" version beloved by the comic artist.
An alternative approach is Moses, who typically lacks a halo but is depicted with two flames sprouting, hornlike, from his forehead. This is because St. Jerome in the Latin Vulgate Bible used the uncommon word cornutus (="shining") in translating ExodusXXXIV. xxix. (Most likely the Latin word, as well as the Hebrew word קָרַן it translated, referred to the spiky appearance of rays of light), but later readers read it as literally derived from cornu, and translated it "horned." (This Danish depiction◊ from ca. 1325) shows Moses with halo and horns.)
The popularity of Halos in Western religious art was, at least in part, to function as Speech Bubbles, putting the prayers of angels or famous Papal quotations as written text on the Halo itself.
In Muslim art canon, Muhammad's head is replaced by flames, if he is depicted at all.
Buddha is often shown with a fiery halo in Buddhist art.
Older Than They Think: Most people think halos as we know them originated in Christian art but late Egyptian religious paintings had gilded round halos, which represented the celestial bodies associated with those gods (e.g., Horus-Moon).
There were "halos" in the Tanakh/Old Testament Bible but they were neither golden rings nor shiny backdrops. They were rainbows deep inside clouds of fire as described by Ezekiel.
Greek sun god Helios was always depicted with a halo. Aspects of Helios were later merged with Apollo, who was also sometimes depicted with a halo when in his solar form.
British comic Augusta plays with this in one strip.
Augusta(Our cute young heroine, to a man she meets who's wearing a halo): Is it hard to get one of those?
Man: Bloody hard.
(The halo vanishes. In the next panel they are seen looking for it under the sofa.)
In the 1980s The Perishers introduced Dirty McSquirty, a character who never bathes and is always surrounded by a halo of flies.
Even thoroughly evil Chaos Marine characters and daemons sometimes have halos, to show their piety, honour and devotion to their infernal masters. Usually these are shaped to echo the eight-pointed star of chaos, which is the universal symbol of the Chaos Powers.
The Dungeon And Dragons 3.5 Book of Exalted Deeds offers the exalted feats "Nimbus of Light" and "Holy Radiance". Nimbus of Light provides illumination and help interact with good creatures. Holy Radiance is a more powerful form, the light hurting The Undead. Those taking a Vow of Poverty are considered very likely to pick both sooner or later, as they're getting free exalted feats, and not that many are worthwhile.
In the more recent Animal Crossing games, you can buy a halo from the Able Sisters to wear on your head.
In Gauntlet 64, they are a powerup that lets you steal life energy from the Death enemies. If you beat the game, you will wear it at all times.
While not strictly a halo, the Fire Tablet artifact in Ōkami creates a circle the the sun's corona around Amaterasu when equipped... and gives her a nice damage reduction to fire and immunity to Lethal Lava Land.
The angelic light spirit Rem in other Tales games often has one. If the Raise Dead spell summons an actual angel, that one too. (The one in Tales of Eternia was Mint with a halo.)
Maxing out the positive end of the Karma Meter in the Fable series will get you one of these, among other changes. The halo isn't always visible, though; it's particularly hard to see in the day.
In World of Warcraft several of the high level priest and paladin armors create halos. There's also an item that grants essentially a halo made of fire, for mages or warlocks.
In several Final Fantasy games like Final Fantasy X, a halo appears over an ally when they have the Auto-Life spell on them. Considering it allows them to come back from the dead...
In Final Fantasy VIII, all three Gardens have halos which hover above them and turn into anti-gravity engines when activated. Only Balamb and Galbadia Gardens actually get to activate theirs, as Trabia Garden is obliterated before its staff figured out how to activate it.
Given to the enemies in Bayonetta, which makes sense, as they're angels. The stronger the angel, the more elaborate the halo becomes.
Infamously, the Cheater's Lament in Team Fortress 2 (though that one is of the "obviously fake halo" subtype, with the wire holding up said halo being blatantly visible from all angles).
Halos are a purchasable costume item during the Valentines Event in City of Heroes. There is a regular shiny golden "good" halo and then the "naughty" halo which looks like it is made of semi-molten iron and always on fire.
Galaxy Angel: the interior of the cockpit of each emblem frame has what appears to be a halo above the pilot's heads. The emblem frames are dependent on their pilot's emotional states in what's even called the Halo System. Although technological the imagery is certainly envoked.
Messiah: A sparkling halo hovers above the head of Bob the angel; it is also used as a visual indicator of who is he possessing right now. People possessed by Satan's imps have a red, horned halo displayed above their head.
Reliquary uses an interesting example of this in Alcolla's angel form: hovering spikes and letters.
The gods of Holystone have these in varying designs and colors.
In the Webster cartoon series, the titular character was an angel who would become fully human merely by taking off his halo and squeezing it into his pocket, and then back into an angel by putting it over his head. The halo itself was a solid object, for all intents and purposes acting like a metal ring. The main villain's primary goal was to steal it for some reason.
In "Keep Calm and Flutter On," Discord gives himself one after being called out on flooding Sweet Apple Acres. "Who, me?"
In the King of the Hill episode "Wings of the Dope," Luanne's ex-boyfriend Buckley (killed in a propane explosion) visits her as an angel. He does not wear a halo until the final scene, in which he pulls one from his back pocket and puts it over his head as he walks away.
In an episode of Rocko's Modern Life, the ferocious and mischievous Earl the bulldog gets adopted by the Bigheads. In one scene he produces a halo over his head when Bev asks him to "play nice" with Ed, then as soon as her back is turned he takes a bite out of the halo, causing it to turn into a pair of devil horns.