The (anti) hero of the book; Lynch is a well-meaning fellow who happens to have been given one of the worst upbringings known to man.
He's tough and resourceful, with a positive outlook on life and a drive to excel in his chosen field (killing).
Lynch does everything with a flair for drama and a pragmatic and methodical approach to his lifelong ambition of exterminating all human life on earth.
He's cool, he's funny, he has a fondness for power tools, and he doesn't like Welshmen. Or residents of Liverpool.
In his own way, a mirror of Lynch, Jake Gutt was given an equally inappropriate (though entirely different) upbringing.
Where Lynch is very much a criminal (though he wouldn't see it that way), Jake is a cop... though perhaps not the most conventional policeman to ever walk a beat. Jake has very strong feelings about the professional benefits of torture, shooting first and asking questions never, selling drugs to make extra cash, drinking binges, and hiring prostitutes to take notes at crime scenes.
Unlike most policemen, he is in no way prejudiced against criminals. He's happy to kill anyone.
Lynch's mother and the one person most responsible for setting him on the path toward mass murder and general destruction. She's sexy. She vicious. She's won several international (though unofficial) awards in the fields of head-butting, groin-kneeing and giving blow jobs.
She may be a lascivious prostitute whose vicious put-downs, beatings and electrocutions of her son frequently leave him unconscious, but deep down she does love Lynch and wants the best for him. Though she'd sooner put him in intensive care than admit it.
A former advertising executive, Samantha leads an exciting life as a vagrant since discovering a previously latent gift for predicting disastrous events. Assailed by visions of impending doom (many of which she herself is responsible for), Samantha blunders through life trying to maintain the sanctity of her cardboard box home while attempting to save the world from Lynch and Jake.
Very much an unconventional vampire, Percy is an accountant who tries a little tyoo hard to fit in, filing down his fang teeth and wearing coloured contact lenses to cover up his glowing red eyes. Finding his blood lust highly inconvenient, Percy does, however, get benefit from his superhuman strength while doing his housework (lifting furniture and such).
Jake's partner on the force. Quim is Jake's foil, generally disapproving of his excesses. He is a stickler for rules and regulations, suggesting ridiculous notions such as gathering evidence before making a conviction (read execution) and dismembering suspects only if really really necessary.
Despite this conservative attitude, Quim does make an exception when it comes to children who spill food down their fronts. He wouldn't go so far as to smash their teeth in with a baseball bat, but a strong scolding would definitely be insufficient.
Lynch's love interest and basically a big-chested bimbo who loves the thrills of being associated with the world's greatest mass murderer outside of Glasgow. Unlike many other characters in the book, Mimsy doesn't see anything wrong with Lynch's murderous appetites and totally "gets" his need to eradicate all life on earth. The fact the police keep trying to stop him is, to her, just plane rude.
She reminds Lynch of his mum.
Henry the Terrorist
Henry is a fully qualified terrorist specialising in cultivating sinister-looking eyebrows and the best way to wear a rucksack. He is one hundred percent convinced in the rightness of his mission to burn all of England in the holy fire of Allah's ignited fart and is more than willing to give his life to the cause, just as long as his thousand virgins have all been given a copy of the Karma Sutra.