Darwin is the dingo of the late Elena Blanc. Darwin also means "Dear Friend" was featured the anime Episode 17 which the studio adapted a special manga chapter.
Darwin is like so many Dingoes that is loyal to their Letter Bee masters. He waited 10 years waiting for Elena to come back to him that never returned because of her death.
Darwin is a white fox-like animal with snow white fur that dirtied in time.
Darwin died after arriving in Elena's grave. He was also buried by Lag beside Elena's grave.