Is there a formal term for a character who exists in the mind of another character, usually to serve as a character foil? I'm thinking of Six in Baltar's head in BSG, Scorpius in Crichton's head in Farscape, the chef in Remy's head in Ratatouille.

"Figment of their imagination" doesn't do it justice, and "shoulder angel" implies, well, tinyness and urging not to eat the last cookie.

Another obligatory attempt to broaden my reading horizons. Opinions on Kate Forsythe? I read the first 40 pages of Rhiannon's Ride in the bookstore and thought it might be worth picking up, but if I do, I'd rather start with something earlier she wrote in this world. I hate diving into a writer's world on book fifty and trying to figure out what the caer'bjeargh is.

For reference: Liked the first Kristen Britain book, was unwowed by Diana Pharaoh Francis's Path of ____ series (well, okay with the first, gave up after second), and I'm guessing Forsythe is somewhere in that realm?