Grenwee is a frog, the joint owner of a railway company along with Purrtoir and Rorgueil, and the victim of Act 1. As such, his personality is unknown.

Day of the incident: Grenwee goes to Baron Rorgueil's mansion for dinner and in order to discuss company shares. He ends up heading oustide into the garden alone, but Caterline follows and eventually kills him with her claws, getting blood on her paws.