The Four Bikers of the Apocalypse

It did not escape their notice that all four strangers had HELL’S ANGELS ON THEIR JACKETS. And they looked dead dodgy as far as the Angels were concerned…
‘You’re Hell’s Angels, then?’ asked Big Ted, sarcastically…
The four strangers nodded.
‘What chapter are you from, then?’
The Tall Stranger looked at Big Ted. Then he stood up. It was a complicated motion; if the shores of the seas of night had deckchairs, they’d open up something like that.
He seemed to be unfolding himself forever.
He wore a dark helmet, completely hiding his features. And it was made of that weird plastic, Big Ted noted. Like, you looked in it, and all you could see was your own face.
REVELATIONS, he said. CHAPTER SIX…

They came down the outside lane of the motorway like destroying angels, which was fair enough…
Pigbog wished he’d paid more attention to the Book of Revelation. If he’d known he was going to be in it, he’d have read it more carefully. ‘What I mean is, they’re the Four Horsemen of the Apocalypse, right?’
‘Bikers,’ said Greaser.
‘Right, Four Bikers of the Apocalypse. War, Famine, Death, and – and the other one. P’lution.’

Terry Pratchett & Neil Gaiman, Good Omens, Gollancz: London, 1990, pp. 262, 274