| ADDERS | Britain's only venomous snakes |
| VIPERS | European -; also known as adders, the only venomous snakes native to Britain (6) |
| VIPER | Britain's only venomous snake, aka adder (5) |
| ADDER | Common European viper, Britain's only venomous snake (5) |
| DAFFYD | Little Britain's 'only gay in the village', ... Thomas (6) |
| CIRCUS | Yarmouth's Hippodrome is Britain's only surviving total ... building (6) |
| BRYONY | With a rootstock once sold as a cheap imitation of mandrake, a wild hedgerow scrambler which is Britain's only native cucurbit (6) |
| ELAPID | Member of a tropical family of venomous snakes (6) |
| MAMBAS | Venomous snakes of sub-Saharan Africa (6) |
| COBRAS | Various types of venomous snakes (6) |
| KRAITS | Brightly-coloured, nonaggressive, venomous snakes of South and South East Asia (6) |
| GORGON | One of three monsters, sisters with sharp fangs and hair of venomous snakes (6) |
| PYTHON | Family of large non-venomous snakes that constrict their prey (6) |
| GILA | ___ monster (only venomous lizard native to the US) |
| SNAKESHEAD | Britain's only native fritillary (6,4) |
| NEWFOREST | Britain's only national park inhabited by all three of our native snakes |
| BRENDANFOSTER | Great Britain's only athletics medallist at the 1976 Olympics (7,6) |
| SLOWWORM | Britain's only legless lizard (8) |
| REDDITCH | Worcestershire town with Britain's only needle museum |
| CAIRNGORMS | National park with Britain's only herd of reindeer |
