The Raven is a recurring motif throughout Life is Strange: Before the Storm.
The raven makes several appearances throughout Episode 1 and Episode 2; its presence goes unnoticed by almost everyone and yet it is often seen in the background. However, it has a dramatic and sometimes frightening presence in Chloe's dreams and is usually seen accompanied by William Price. The raven seems to have taken a particular interest in Chloe herself as it can often be seen watching her (and people associated with her) throughout both episodes and seemingly influencing her dreams of her father to some unknown end.
The raven is said to represent transformation and is also feared as a "trickster spirit." A common saying the Native American tribes in the area Arcadia Bay was built on said about the raven: "The raven is to be respected but never trusted."
In the Native American stories, the trickster is the protagonist of most tales, and her or his actions, while not meant to change the world, end up having a profound impact upon the world. In this sense, the raven in Before the Storm symbolizes Rachel.