One of the main characters from Grant Morrison's Invisibles.
Jack Frost is a white teenager from Liverpool. He is pretty short, and he has scruffy blonde hair and blue eyes. He always dresses casually, having no truck with the whole superspy image or any of that sort of stuff. He barely even accepts his codename, let alone having a mask or an outfit. Jack is about the simplest bloke you're likely to meet - he just doesn't give a fuck. That said, he is the key to the whole operation, and becomes more powerful than any of the rest of the cell.
The name Jack Frost comes from folklore, as explained above, and is often used in England as a personification of frost or ice. In Dane's case, Jack Frost refers to the defense mechanism in Dane's psyche that keeps him from feeling the pain of his father's desertion, with the unfortunate side-effect of keeping him from feeling many more things as well. For Dane to accept the name is for him to acknowledge this repression, and thus to be able to grow.
Life and times
A lot of the comics focus on Jack's story in a fairly linear way, so I'll skip through it fairly briefly.
Obviously, this might spoil the story for you a bit.
Jack Frost is born Dane McGowan, in Liverpool, England, around 1980. His father leaves the family when Dane is young.
At about fifteen years of age, Dane is restless and frustrated. He is troubled by visions and spirits, and reacts with violence and apathy. When he and his friend Gaz firebomb their school and Dane attacks his history teacher, they are sentenced to a term in Harmony House. King Mob busts Dane out and leaves him in London in the hands of Tom O'Bedlam for training.
Tom teaches Dane his secrets over the period of a year or so. When Tom feels that his work is done, he passes his earthly power onto Dane, and they jump together from the roof of Canary Wharf. Tom is killed, and Dane is knocked into the dimension of the Academy.
At this point, we'll start calling him Jack, though he does not fully accept the name for a while.
Jack tentatively joins KM's cell, filling the gap left by John A'Dreams. He accompanies King Mob, Lord Fanny, Ragged Robin and Boy on a psychic time-travel mission to retrieve the Marquis de Sade from history. When this mission goes wrong, Jack is left missing the tip of a finger. He takes KM's gun and car and absconds, straight into the hands of the enemy. He escapes both the good and bad guys, but only by killing an enemy soldier. This affects Jack very deeply, and he tries to return to his former life, returning to Liverpool and visiting Gaz, and his mother. Neither of them are sufficiently open-minded to help him - they are both pretty freaked out by what he is telling them. The more he sees that his past self is dead, the more his future self opens up to him: he is able to use Tom's magic to avoid being captured by the enemy. He is willingly retrieved by Boy and Brian Malcolm, his old history teacher (who, it turns out, is just one of the identities of the powerful Invisible agent Mister Six).
They head to London to rescue King Mob and Lord Fanny, who are being held prisoner by the bad guys. While Fanny is rescuing KM, Jack is ensnared by the powerful archon, the King-of-all-Tears. Jack's teaching kicks in, and he surrounds himself in a protective circle (backed up the while by Mister Six). The King-of-all-Tears tries every trick at his disposal to get Jack out of the circle, but Jack's nonchalant power proves too great for him, and he retreats. Through this trial, Jack learns more and more about his own nature. He has a uniquely strong link with Barbelith, a rescue buoy for the whole universe. In its communication with him, Barbelith addresses Jack and all of us interchangeably. Jack begins to understand that his destiny and that of all the rest of us are very closely linked.
Jack is able to bring KM back to life using magic mirror. He then saves the life of Sir Miles, even though the latter is a Terrible Bad Guy! Jack, it seems, is an Invisible of some new school.
The team repair to Mason Lang's in New York to recover, and Boy continues to teach Jack to fight. Jack takes over the Water role in the team from Fanny.
Jack assists Fanny with perimeter defence when the team break into the Dulce installation for the first time.
Jack and Fanny are charged with the responsibility of getting the Hand of Glory from the Harlequinade. They have a strange old time of it, but they don't take any crap off the Harlequin, and they are awarded the Hand for their marvellous dancing.
Jack is instrumental in tracking down Boy when she goes missing.
When the team re-enter the Dulce facility, Jack is once again on perimeter duty. However, he is taken by the bad guys and ends up with the Mysterious Cryptic Chess-Playing Bastard, a being of extreme power and meta-ness. Chess Bastard (as we shall call him, for short) interviews Jack in a fairly well-mannered way, and then takes him to the heart of the base and into the store of magic mirror that is kept there. Jack is left in a fever for several days after this experience.
The bad guys are preparing to bring down the Archon of the next age, at a royal ceremony in Westminster Abbey, during the 2000 solar eclipse. Jack and Jolly Roger infiltrate and sabotage the flotation tanks of the ciphermen who guard the perimeter of the abbey. Jack is confidently using various kinds of meta-linguistic trickery.
At the abbey, it transpires that the bad guys had plans of their own for Jack - he is to be the vessel for the new Archon. Luckily, Jack and the gang are prepared for this, and Jack eats the Archon.
Jack and Fanny start their own cell, along more mystical and less shooty lines than the old one, and live happily ever after, until 2012, when the world ends.
On that last day, Jack, Fanny, Helga and Takashi gather together to send Robin back to 1988, and to hold off the Archons that break through at this point.
Robin arrives back in the future, the universe evolves out of its linguistic prison, and Jack Frost has the last line of the story:
"Our sentence is up".