Like the progenitors of her kind, Orphie is the victim of a forced transformation. However, she is adamant that she was something other than a normal bat before her change.

Some have theorized she may have been the recipient of a Reincarnate spell that went awry, while others suggest she may have been permanently transformed by similar magic to that which created the Nocturne in the first place, just on a smaller and more targeted scale.
Some have even proposed the whole thing is a delusional fantasy of hers constructed to cope with the dire situation Aravoxa is in.

What is for sure, though, is that Orphie seems to have no special loyalty reserved for other Nocturne, and goes out of her way to connect with others, while simultaneously fretting about how they may perceive her due to her 'monstrous' form. While she isn't certain what species she supposedly used to be, she is confident it was one of the more common Humanoid species. The fact she can speak fluent Dwarvish and Gnomish may be a clue.

Further evidence to support her leading a different life before now is the depth of her training. Nimble, strong-willed and with seemingly supernatural abilities that you'd expect from a Monk with a decade of practice.

Now, though, she's found herself leading the life of a scrounger.

Although she objects to more grand acts of larceny, she seems to have no trouble spending time with Skraz Pricklepluck. Indeed, she struggles to resist his doe-eyed looks and scrappy charms, and has been a patsy to him on more than one occasion, sometimes even sharing in the spoils. Her relationship with him is a black mark on her otherwise spotless record in terms of law and trust.

On the other hand, Orphie's relationship with Selene Rootborn is a far more wholesome one. During the early days after whatever transformation or traumatic experience befell Orphie, she was a miserable wreck prone to fits of tears. During this time, Selene was one to help her find her feet, be it out of genuine care or merely a deep well of patience and gritted teeth.
Since then, Orphie has been grateful towards the woman, and intent on finding ways to pay her back, regardless of if she feels she deserves it or not.