Spider, given the designation CT-1123, was a Clone Captain within the Grand Army of the Republic. He was a clone trooper who commanded a company of troopers. Throughout the duration of the Clone Wars, Captain Spider fought alongside Jedi General Tualon Yaluna, until Supreme Chancellor Palpatine issued Order 66 to him and his unit. Following this order, Spider's unit killed Jedi Knight Sunghi Silpari. Subsequently, acting on Palpatine's orders, they apprehended the Jedi Iskat Akaris and transported her to Coruscant, where Akaris became a member of the Inquisitorius known as the Thirteenth Sister. He held the military rank of Clone Captain.
A spider tattoo adorned Captain Spider's head. His hairstyle consisted of long hair on top with the sides shaved. Furthermore, he colored his hair brown.