The Scorpion Imagin is an evil Imagin and an antagonist in episodes 23 and 24 of Kamen Rider Den-O.
Kamen Rider Den-O
The the Scorpion Imagin made a contract with Masuda to abduct Shiori for him. After going back in time, the Scorpion Imagin fought Den-O's Rod Form before being destroyed by Den-O in Ax Form.
Kamen Rider Decade
World of Black RX
World of the Rider War
OOO, Den-O, Let's Go Kamen Riders
In the altered timeline where Shocker conquered the world, the Scorpion Imagin was one of the monsters who served the organization in the alternate present.