It is the largest butterfly in Europe, wearing a chestnut velvet coat and a white fur tie. The wings are covered with gray spots, and a pale zigzag line passes through them. The periphery of the line is grayish white, and there is a circular spot in the center of the wing, just like a big black eye, with rainbow-like unpredictable colors flashing in the pupil, such as black, white, maroon and cockscomb red.