Arlo has short, slightly curly, light-ish, brown hair with a fringe that is constantly nearly in his eyes which are blue. They have relatively pale skin and freckles across his cheeks and nose. There nose is slightly upturned and small and he has thin lips. His face is a diamond shape. He is taller than average.

Arlo goes by any pronouns and is rather unsure of herself. He is rather shy but once close to someone can be charismatic and funny. They are an ISTP however she appreciates the people he is closest to and is incredibly reliable often to their own downfall as they can be guaranteed to be there for anyone, not helped by him being too socially awkward to say no. They enjoy nature and her favourite colour is green.

Arlo has a strong relationship with his family and they grew up on the edge of Briton with the country side close by. She loves running and exploring the country and was able to play quidditch in a secluded field. However their family will only use he/him for Arlo as they are rather uptight and she hasn't gained the courage to tell them about their gender yet.The're parents are Leila and Mark Nightingale. Leila is an auror so not at home much however when she is, is constantly teaching Arlo about magic. Mark is a chef and a muggle who is at home much more often. He often holds film nights for the children with classic muggle films (Arlo's favorite is Star Wars). She has two siblings Hope (older) and Luke (younger). They went to a muggle primary school as Hope didn't inherit magic and so Arlo wasn't expected to either. It is yet to be seen if Luke will display any sighns of magic.

At the age of six her mother's side of the family came over for a family gathering and over the night he became overwhelmed. They started crying on the floor in the cupboard for their teddy (a comfort blanket at the time) and eventually it just flew into her grasp and so was finally noticed by everyone. This lead his muggle father to believe she was a jedi leaving her mother's family wandering what a jedi is.