Eldon Elsrickle (fl. early 1600s) was a wizard and a thief who was responsible for the introduction of the Unlocking Charm to Britain, in the early 17th century. Elsrickle was a famed thief, who was behind a series of mysterious robberies in London, earning him the sobriquet of "The Spectral Thief of Old London Town".
Elsrickle had fled from his native Britain to Africa, hoping to escape punishment for a series of robberies. Whilst there, he obtained two prized treasures: a Nundu cub, and a little known-charm otherwise known as "The Thief's Friend" that he learn from an ancient African sorcerer: Alohomora.
After some time in Africa, Elsrickle returned to London heavily disguised. He used the Nundu cub to guard his house when he was not there (recurring to Stunning Spells through the keyhole whenever he entered the house). With the knowledge of a spell that subtly unlocked doors, Elsrickle carried on with his thievery and soon he was taking home priceless treasures and antiques from all over London — making front page news on Muggle and wizarding newspapers alike.
Elsrickle was surprised a few times in the house of fellow wizards, but whenever this happened, the thieve offered to trade his Unlocking Charm for his freedom. This deal was accepted so many times, that before long, there were many "Spectral Thieves" ransacking the houses of London. Elsrickle was confident, however, that no one could rob his house, as it was guarded by his ever-growing Nundu.
Blagdon Blay, a fellow wizard Londoner, had his house broken into nineteen times in the course of two weeks. He managed to develop an Anti-Alohomora Charm to secure his house, and soon all the London wizards sealed their houses shut at night, and special wizard task-forces protected those of Muggles. Frustrated and angry about not managed to rob one single house, Elsrickle got home one morning, but forgot to Stun his Nundu — the beast proceeded to devour him and, effectively, his last word was "Alohomora".
- Wonderbook: Book of Spells (First appearance)