Grimalkins are typically monotheistic but do believe in the realms of spirit. The Great Mother Goddess is our deity who can appear in many forms. The Great Mother made the cosmos, made our world and the worlds beyond. Despite being monotheistic, Grimalkins do not have a religion. The reverence of the Great Mother is faith-based, that is to say, each Grimalkin honours Her in their own way. There is no doctrine or dogma, no holy scriptures that tell one how to honour Her. There is only the Old Grimalkin Book of Thalaig that sets out guidelines as to how a Grimalkin should conduct oneself and one’s spiritual affairs, and offers wisdom and comfort to those who seek it.
The Old Grimalkin Book of Thalaig is the Grimalkin Bible and contains all the rituals and ceremonies a Grimalkin needs from Pawfasting to funeral rites. Anyone can contribute to the Book - there is no dogma or organised religion. The Book also contains poems, prose, readings and sayings, words of wisdom Grimalkins can find comfort in. The Book has been added to over the milennia and there are currently 50 volumes of the Book to date.