Cuddles used to be a 'bad' Dementor, which is the most common to find. They are the ones that suck the happiness out of you and whose kiss can kill you. One day, though, while on the Hogwarts Express a student named Freddie Weasley helped show her love and she turned into the very rare 'good' Dementor. Her appearance changed to that of a human, with the exception that her features are mostly pink or pink tinted. Soon after she became Freddie's pet and he named her Cuddles. She is also, in reality, 62 years old but she only looks around the age of 16 because Dementors age 4x slower than humans. It is speculated that she will probably age at the same speed of a human now but nobody is sure as of yet.
Later Cuddles formed friendships with most of the Weasleys, and was even informed by Brielle Weasley that she was an "Adopted member of the family". While Cuddles has not officially changed her name she refers to herself as a Weasley and calls Fleur and Ginny her Aunties.
Not long after she began attending Hogwarts she found out through Voldemort that her breed of Dementor is the complete opposit of the 'bad Dementors'. She lives off chocolate, her kiss can heal a soul, she gives off a warm aura instead of a chilly one. He used her to heal her soul and then had her kidnapped.
Voldemort began to seduce Cuddles in order to break her, make her pliable, but instead ended up getting her pregnant and deciding the use the child as leverage against her. Sex then became just for pleasure instead of an act with a hidden agenda. This caused a new ship to be created known as Cuddlemort.
Cuddles is controlled by Reine.