Azumi is the human form of the Serpent Undead, the Category Queen of Diamonds Undead.
Kamen Rider Dcade
A medusa-like monster that is hunting for the Joker, having the Tortoise Undead to aid her. Her hair changes to snakes and can be used as whips, and she has that hysterical laugh all the time, even in public, somewhat a psychotic person. She was wounded by Ryo Mikami, Hajime Aikawa's look alike, and sealed by Chalice, who gives the sealed Absorb Serpent card to Garren to successfully assume his own Jack Form.
OOO, Den-O, All Riders: Let's Go Kamen Riders
A Category Queen of Diamonds Undead. In Let's Go Kamen Riders' altered timeline, like the other Undead, she follows Kerberus orders', and accompanies him to the meeting with Shocker.