Pitch is a deepfae - a variant of fae native to the deepest caverns of the underground, characterized by their large eyes, bright coloration, and smaller bodies, which typically lead to somewhat goblin-esque appearances.
Deepfae are a rare occurance outside of their native caverns, Pitch being a rare case of one that ventured into the larger underground. She found employment as a tunneler working for a company that builds transport lines in the underground, a job that generally underpays and undervalues her. But, between mild stigma against deepfae and her lack of professional training, it's all she's got to work with.