Great Britain

Great Britain is a large European island, to the northwest of the main continent. The island is administrated by the United Kingdom, which consists of England, Scotland, Wales, and Northern Ireland (which shares an island with Ireland) in the Muggle world, and by the Ministry of Magic in the wizarding world.

Magical creatures and plants

The Kelpie is native to Britain, as well as Ireland.

England

The Bowtruckle is native to England, as well as Germany and Scandinavia.
The Crup, a wizard-bred dog, is native to England.
The Dirigible plum can be found in Ottery St. Catchpole, growing around the Lovegood House.
The native range of the Hag is England, as well as Europe and Russia.
The Porlock is a horse guardian native to England, as well as southern Ireland.
Wild Ponies can be found in the New Forest in Hampshire, England.

Scotland

Aconite
The native range of the Banshee is Scotland, as well as Ireland.
Blast-Ended Skrewts were illegally bred in Scotland by Rubeus Hagrid.
Blood-Sucking Bugbears
Bubotubers can be found in Scotland, in the Forbidden Forest.
Devil's Snare
There is a Giant Squid residing in Hogwarts Lake.
The Hebridean Black Dragon, is native to the Hebrides Islands.
Nessie, the world's largest Kelpie, can be found in Loch Ness, Scotland.
The Moondew is a flowering plant found in Scotland, and possibly Ireland.
The Ogre is native to Scotland.
The Quintaped can be found on the Isle of Drear.
The Scottish stag, known for its impressive horns, is native to Scotland.
There is a Thestral herd residing at Hogwarts School of Witchcraft and Wizardry.
The Vampyr Mosp may be native to Scotland, as they are frequently found in the sewers, pipes and greenhouses of Hogwarts School of Witchcraft and Wizardry.
The Weetimorousbeastie is a fabled creature that allegedly lives on the banks of the River Clyde.
The Wiggenbush

Wales

The Common Welsh Green is native to Wales.

Magical games and sports

The British and Irish Quidditch League

England

The Appleby Arrows
The Chudley Cannons
The English National Quidditch team
The Falmouth Falcons
Shuntbumps is a popular game in Devon.
Swivenhodge is a broom game that began in Herefordshire.
The Tutshill Tornados
The Wimbourne Wasps

Scotland

The Banchory Bangers were a Scottish Quidditch team noted for their poor skills and post-match parties, but were disbanded in 1814.
Creaothceann originated in Scotland, and is regarded as the most dangerous of all broom games.
Montrose Magpies
Pride of Portree
The Scottish National Quidditch team
Wigtown Wanderers

Wales

Northern Ireland

The Ballycastle Bats

Food and beverages

A Cornish pastie is a pastry from Cornwall, England.
The source of the sparkling beverage McSpratts is in the Vale of McGowan in the Scottish Highlands.
Quintin Black was a brand of alcohol produced and sold in Scotland by the Quintin family.
Yorkshire pudding is a dish that originated in Yorkshire, England.