River Thames, London, England

The greater weever, a ferocious fish which can grow to 20 inches long with venomous spines, has been discovered in the Thames river for the first time ever. The creature lurks below the seabed waiting for its prey.

If stepped on their razor sharp teeth cause painful swelling for up to two weeks. Multiple attacks have even been known to kill. But it's not all bad; the fish is attracted to London's famous river because pollution levels have dropped significantly within the last 50 years prompting numerous old creatures to return alongside some new beasts.