One of the standout displays at this year's Antiques for Everyone Winter Fair will be a small flock of rather grotesque-looking birds. Unlikely though they may seem, these birds have become among the most sought-after collectors' items of early 20th century art, with prices reaching as high as £94,800 at auction (a record set in 2014).

Want to learn more about the history of art but not sure where to start? We've made a list of the best art history and appreciation courses and lectures available online.

The fantastical birds, which mightn't look out of place on a Harry Potter film set, come from the studio of the Martin Brothers – Robert Wallace, Walter Fraser, Edwin, and Charles Douglas – who set up a pottery together in Fulham, London, in 1873. Robert Wallace, the eldest, had worked as a stone carver on Pugin and Barry's new parliament buildings in the mid-19th century and brought his experience of creating gothic gargoyles and mysterious animals to the brothers' ceramics venture.

A Martin Brothers' Pottery bird

It was Robert Wallace who came up with the idea of the birds, each of which has its own unique (and often knowing) expression. Walter Fraser provided the technical expertise needed to realise his elder brother's designs, specialising in the coloured glazes, while Edwin did most of the throwing and decorating. Charles Douglas was in charge of running the shop and was known to hide the finest pieces away – sometimes under floorboards – for the best clients.

Some of the birds are statuettes while others are pots and covers, and others are formed as jugs. A number of the caricatured faces were intended to resemble leading figures of the Victorian era including Gladstone and Disraeli.

Despite the weighty price tag, Antiques Roadshow expert Will Farmer says that these birds are worthy investments: 'In my thirty years working in the decorative arts I have never known these items depreciate. They keep climbing year on year. They tick all the right boxes: rarity, scarcity, fine quality, and the craftsmanship is exquisite!'

The display at Antiques for Everyone, which will comprise four of the Martin Brothers birds, is brought to the fair by specialist dealer Alison Davey of AD Antiques (pictured top). Thanks to the limited supply and high demand the most valuable of the quartet is on sale for £68,000.

Even if the price is somewhat out of reach, as a testament to originality and the birth of studio pottery, it is worth seeing these pieces in the flesh, if only to marvel at those enigmatically ugly expressions.