Insanity Sans is characterized by his unpredictable and erratic behavior. He is often portrayed as being mentally unstable and prone to outbursts of violence. His physical appearance may include dark circles around his eyes, disheveled clothing, and a maniacal grin. Dust Sans, on the other hand, is a more menacing and ominous character. He is often depicted as being associated with death and the underworld. Glowing red eyes and a blue cloak. Dust Sans is know for being sadistic.