A mysterious looking Yo-kai with pale mint-grey skin and small eyes shadowed by his hat. He has very long hair that starts as grey and seeps into a gradient of turquoise towards the bottom, worn with a brown hat that has a dark grey strap around the center. He wears a blue kimono with a plain yellow sash and a pair of zori sandals with toe straps.
Medal Swap: "You have grass in this town? Cool. That's super exciting...kind of."
"Kusakui Otoko" is derived from "Herbivore Man" (Japanese: 草食い男,Kusa-kui Otoko).
"Herbiboy" combines "herbivore" and "boy".
"Acelgo" (spanish name) is a corruption of "acelga" (chard).
Herbiboy is based on the real-life Japanese phenomena of the Herbivore Men (Japanese: 草食(系)男子,Sōshoku(-kei) danshi), a term used to describe men who have no interest in getting married or finding a girlfriend.