Arachne has blue hair, black eyes and a dark grey/black outfit visible while wearing his Cloth. His casual attire has not been revealed.
Arachne is a ruthless Saint, not hesitating by the least to kill humans younger than himself, as witnessed when he tries to hurl Kiki against a bunch of rocks.
When he tries to kill Kiki because he does not reveal Mu's location (due to him not even knowing), Seiya arrives and saves Kiki, changing Arachne's goal to kill Seiya instead in order to avenge the deaths of the other Silver Saints who got beaten by Seiya and his friends. Gaining the upper hand because of Seiya not wearing his Cloth, Arachne is almost successful in killing the Pegasus, but Sho arrives to rescue Seiya. As he holds Arachne of, Seiya is able to break free from the webbing he is held by, gathers his Cosmo again and equips the Pegasus Cloth, easily defeating Arachne.
Tarantula Net: Arachne sends a wave of purple network which slowly drains the opponent of his energy, which also means certain death for the opponent.
Arachne wears the Tarantula Silver Cloth which covers a moderate amount of his body. The Cloth has a dark-green/brown color, with a few blue and black stripes. His helmet also resembles a tarantula, with red eyes and spider-like shape on his helmet.