Kayaba Akihiko is the only player in Sword Art Online whose avatar does not match his appearance in the real world. As a result, Akihiko’s avatar, Heathcliff, bears no resemblance to his true skinny body at all. Significantly idealized, Heathcliff was muscular, tall, and physically strong. He was almost always seen wearing the colors of the Knights of the Blood.
At the start of Sword Art Online, Akihiko appeared to the trapped players as a huge faceless, hooded person with a cloak as his Game Master avatar.