|This article is about a/an Dopant identity in Kamen Rider W.|
- Height: 220cm
- Weight: 138kg
The Cockroach Dopant's abilities include the ability to climb along walls and to move faster than oncoming attacks, much like a cockroach. Only Kamen Rider Double LunaTrigger's homing attacks are able to hit it.
- Main article: Ikari
The main user of the Cockroach Memory was Ikari (伊刈), a sociopathic dōjinshi artist who ran the Dark Bug Exterminator website, a blog where people wrote down the names of those they want dead and he carried out the deed as the Cockroach Dopant (コックローチ・ドーパント Kokkurōchi Dōpanto), writing about his adventures in his self-published manga as the hero "Gokistar" (ゴキスター Gokisutā, portmanteau of "Cockroach" (ゴキブリ Gokuburi) and "star"). With his Dopant form's speed, he stole the Luna, Trigger, Heat, and Metal Memories from Kamen Rider Double. Ikari then decided to take the rest of Double's arsenal to become more powerful. However, after Philip learnt the Heaven's Tornado dance and used it against the Cockroach Dopant, the Gaia Memories are retrieved, allowing for the Cockroach Memory to be destroyed by Double LunaTrigger's Trigger Full Burst Maximum Drive.
- Main article: C
A member of EXE, known as "C" (Ｃ（シー） Shī), possessed a second Cockroach Memory (コックローチメモリ Kokkurōchi Memori). He transformed into the Cockroach Dopant (コックローチ・ドーパント Kokkurōchi Dōpanto) to fight Shotaro as Kamen Rider Joker, but was easily defeated by his Rider Kick.
Super Hero Taisen
However, a revived Cockroach Dopant appeared in Kamen Rider × Super Sentai: Super Hero Taisen as a member of Dai-Shocker. The Dai-Shocker later revealed their alliance with Dai-Zangyack and battled an army of Kamen Riders and Super Sentai. He was seen fighting TimePink, GingaYellow, MagiBlue, and Kamen Rider 1, but his fate wasn't certain in the movie, or his human identity.
Movie War Ultimatum
The Cockroach Dopant makes an reappearance in Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum, as one of the revived members of the Monster Army that Wizard faced in his portion of the movie. He ran off when Poitrine finished off the grunts that had followed them.