Suga Kenji (菅 賢治), born 1955, is the Chief Producer of Gaki no Tsukai.
He is regularly seen as an active side participant in the annual Batsu Games, where he appears at the end of the game in various characters related to the game's theme, wishing the participants a Happy New Year. Starting as an in-joke, his nickname Gaa-suu has been regularly featured in said games as part of the name of whatever institution the participants are working in (e.g. "Gaa-suu Blackluster Airline System"). His face is also featured on statues placed in front of the building, supposedly of the institution's founder etc., as a laugh trap.
He is a regular participant in the Shichi Henge.