Some famous breaches of the Code of Wizarding Secrecy have occurred, most notably the Ilfracombe Incident and the many times Muggles have spotted the kelpie in Loch Ness or the Yeti in the mountains of Tibet. However, Muggles are typically kept in the dark about magical creatures.

Tilly Toke
1903-1991
Recipient of the [Order of Merlin] First Class as a result of the Ilfracombe dragon attack of 1932. An errant Welsh Green dragon attacked a beach full of sunbathers. Tilly and her family were credited with saving [Muggle] lives as well as wiping their memory afterwards. One Muggle, however, known as "Dodgy Dirk," is known to tell tales of a "dirty great flying lizard" that attacked him way back when. His story is not believed by other Muggles.

Tilly Toke
1903 - 1991
Gained Order of Merlin, First Class, for saving Muggle lives during the Ilfracombe Incident of 1932, when a dragon swooped down on a beach full of sunbathers.