An awakened shrub they found standing under a sewer grate, moving around in the sewer as the beam of sunlight shifted about. Discarded by a wizard as trash, it literally grew up with his roots digesting the town's shit. It grew good berries, and offered the party some when they encountered it in a session one "rats in the sewers" scenario. They immediately adopted it, and it became their mascot of sorts, named "Stem". I had a great time RPing Stem, with this child-like wide eyed wonder as the party took it out to explore the world with them.