|This article is about a/an Dopant identity in Kamen Rider W.|
The Spider Dopant uses threads called the Spider Web to attack and implant the small but destructive Spider Bombs into humans that would spin silk around a person's loved ones and explode on touch. Unlike future Dopants who lived from their Memory Breaks, Matsu died from the Spider Memory's side effects after it was destroyed because the Gaia Memories were still in developmental stages at that time.
- Main article: Seiichiro Matsui
The main user of the Spider Memory was Seiichiro Matsui (松井 誠一郎 Matsui Seiichirō).
The first 1:30 minute trailer for the movie showed a revived Spider Dopant facing Kamen Rider Accel in the battlefield of the final battle against the Dai-Shocker and Dai-Zangyack Alliance. However, the scene was cut from the final version of the movie.
Kamen Rider Gaim: Sengoku Battle Royale!
A Spider Dopant appears as part of a group of four Dopants along with Death Dopant, Bat Dopant, and Eyes Dopant, accompanying Kamen Rider Bujin Gaim and the Nepenthes Monster in his attack on the Double Army. The Dopants are met by Bujin Double, who assumes CycloneJokerXtreme. The four Dopants are soon destroyed by Bujin Double's Prism Bicker's Bicker Charge Break Maximum Drive.