獬豬 - kaichi

…Thus, although there are cases where the shapes of komainu and lions are confused, in the Heian period they were clearly distinguished. For example, lions and komainu were placed in front of the curtains of the Seiryoden or on the chinzu curtains of the Emperor and Empress, with the one with its mouth open being placed on the left as the lion, and the one with its mouth closed and with one horn on its head (a beast called a kaichi, which is said to know well whether people are right or wrong) being placed on the right as the komainu. Lions and komainu were also found in Bugaku of the time, and their shapes remain in Shinzei's Kogakuzu. …

*Some of the terminology explanations that mention "獬豸" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…したがって狛犬と獅子と形を混同したものがあるが，平安時代には明確に区別していた。たとえば清涼殿の御帳前や天皇や皇后の帳帷の鎮子（ちんず）には獅子と狛犬が置かれ，口を開いたのを獅子として左に置き，口を閉じ頭に1角をもつもの(人の邪正をよく知るという獬豸（かいち）といわれる獣)を狛犬として右に置いた。また当時の舞楽の中にも獅子と狛犬があり，信西の《古楽図》の中にもその形が残されている。…

※「獬豸」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報