The wildcat's future is threatened by interbreeding with domestic cats
The Scottish wildcat is featuring on a new stamp which aims to highlight the plight of endangered animals in the UK.
Experts believe there could be as few as 400 wildcats left in the wild, making it even rarer than the Bengal tiger.
The survival of the wildcat, also known as the Highland tiger, is threatened by interbreeding with domestic cats.
Dr David Hetherington, of Cairngorms Wildcat Project, said the "iconic" animal was now seriously endangered.
But he added: "If everyone pulls together, for example by making sure their pet cats are neutered and vaccinated and by reporting wildcat sightings, I'm sure we can save our Highland tiger from extinction."
Helping to launch the stamp was Seasaidh, a three-year-old Scottish wildcat from the Highland Wildlife Park, near Kincraig, Kingussie.
The 1st class stamp is one of 10 featuring British animals facing a struggle to survive, part of a series produced by the Royal Mail to celebrate the International Year of Biodiversity in 2010.
Ian McKay, Royal Mail director of Scottish affairs, said: "These stamps allow us all to have our own collection of miniature mammals, including the Scottish wildcat.
"They will also deliver an important conservation message through millions of letter boxes, highlighting just how important it is to safeguard the future of the diverse range of mammals which inhabit the UK and its shores."