Isaac Dan der Grimnebulin is a human scientist, and one of the main characters in Perdido Street Station (novel). He was formerly a professor at New Crobuzon University, working under Vermishank, but left that job after finding that he was not any good at teaching. He works freelance assignments for the university to have access to its laboratories and purloining scientifc equipment whenever possible, while also making a living selling his services to people in need of his advanced science. He is described as "brilliant" and "undisciplined."