Simon Says is the akumatized villain of Simon Grimault.
As Simon Says, he is outspoken, eccentric, commanding, and overconfident. He thinks fast and uses his cards wisely to get people to do what he wants them to. He is persistent in succeeding to get revenge on Gabriel and get Ladybug and Cat Noir's Miraculouses for Hawk Moth.
- His villain form also appears in the theme song animatic.
- His villain name is based on the game "Simon Says", where a player is Simon and orders people to do something, but the other players must obey only if the orders start with "Simon says...".
- In the French version, his name is Jacques Grimault, which is a reference to the French version of "Simon Says" called "Jacques à dit."
- His villain name in the French version is Jackady.
- A statue of Simon Says appears in the Musée Grévin in "The Puppeteer 2".