Moonwater

Lupin is a half-blood, born, according to the series, to wizard Lyall Lupin and his Muggle wife Hope Howell on 10 March 1960. He was bitten by the vicious werewolf Fenrir Greyback when he was a small child, and became infected with lycanthropy; the condition being incurable, he was doomed to live his life as a werewolf. Lupin and his parents feared he would be unable to attend Hogwarts, but headmaster Albus Dumbledore allowed him to enroll—provided certain protective measures were taken. A house was built in Hogsmeade with a secret passage leading to it from under the Whomping Willow. Lupin was smuggled into and confined in this house for his monthly transformations. The transformation from human to werewolf is difficult and painful, and if the creature is isolated, it will become frustrated and harm itself if unable to attack. The villagers mistook Lupin's howling as extremely violent ghosts. The house was dubbed "the Shrieking Shack" and became known as the most haunted building in Britain. Although it was never actually haunted, Dumbledore promoted this rumour to discourage curious villagers from exploring.

When Lupin started Hogwarts, his condition was kept secret, but James Potter, Sirius Black and Peter Pettigrew deduced the truth in their second year. By their fifth year, they secretly and illegally learned how to become Animagi to keep Lupin company during his transformations. His lycanthropy was not transmittable to them in their Animagus forms, nor was he a threat to them while they were animals. Additionally, James and Sirius' Animagi, a stag and a large dog, were large enough to control a werewolf. His friends nicknamed him "Moony" for his condition.

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Regulus Arcturus Black was an English pure-blood wizard, the youngest son of Orion and Walburga Black, and the younger brother of Sirius Black.

Regulus was born in 1961 into the wealthy, pure-blooded Black family, as the youngest son of Orion and Walburga Black and younger brother of Sirius Black. It is assumed that he was named after his great-uncle, also named Regulus, and his paternal grandfather, Arcturus. Relatives included Bellatrix Lestrange, a loyal Death Eater of Lord Voldemort's

Regulus's parents considered him to be much different from his older brother Sirius Black. Although Sirius was the older son and heir, he didn't in any way whatsoever follow the Black family traditions, unlike Regulus. Their parents disapproved of this, and Sirius was later Sorted into Gryffindor house when he attended Hogwarts, causing an even bigger strain on his relationship with the rest of the family.

Following this, Sirius left home at the age of sixteen and was subsequently disowned and burned from the family tapestry by his parents like Andromeda Tonks a few years before. Regulus, on the other hand, was admired by his parents for his loyalty towards his family and upholding their traditions.