Hiyosu

is a department head in the Research Institute tied to the 12th division.

Character Outline
He is a large, green man with a bulbous head and an extendible eyeball via a crank on his head. He was the one that originally discovered Rukia Kuchiki's unusual Gigai. He was also present when the Research Institute discovered that Yammy Rialgo and Ulquiorra Cifer had begun a small invasion on Karakura Town.

Trivia

 * He is one of the few Shinigami within the Gotei 13 who doesn't take on the appearance of a Human.

Hiyosu