On first class letters (26p) the Queen's head will be substantially overshadowed by that of Bram Stoker's Dracula, staring up at you from the envelope with red eyes and nicely protruding fangs.
On more expensive postal items you will find Mary Shelley's Frankenstein's monster giving you a stiff-necked glare (31p), the split face of Robert Louis Stevenson's Dr Jekyll and Mr Hyde (37p) and the gaping jaws of Sir Arthur Conan Doyle's Hound of the Baskervilles (43p).
The Post Office is capitalising on this year being a double anniversary in the annals of famous horror stories: the bicentenary of Frankenstein and the centenary of Dracula. It has commissioned the artist Ian Pollock to create monster likenesses true to the authors' ideas and not the popular images put forward by B-grade horror films.
Fans hope the four portraits will help win people back to the original tales. "Very few people have read Dracula and almost no one has read Shelley's Frankenstein," said Tina Rath of London's Dracula Society, which will celebrate the classic tale's centenary on 18 May.
"We must do it well because these classics have endured for so long. They still remain as popular today all over the world as when they were published," said the Royal Mail's Rowan Andrews. "The royal family are the only living people allowed to be on British stamps. We've broken with convention by featuring the first living-dead person - Dracula the vampire."
In a first for stamp art design, special ultra-violet colouring has been used to give the characters a suitably eerie "glow-in-the-dark" appearance. They highlight Dr Jekyll's transformation into the pale Mr Hyde, the fearsome fangs of the Baskerville hound, the bolts of lightning symbolic of the Frankenstein monster's creation and the moonlight of Dracula's world.
Special stamps like these are big business for the Royal Mail - selling up to pounds 90m worth a year in the UK and pounds 5m overseas.