Chinese idioms (成语 cheng2yu3) are idioms from China. They are most commonly four characters long.
List
There are too many chengyu.
井底之蛙 (jing2 di3 zhi1 wa1)
Literally "frog in at the bottom of the well", referring to ignorance.
Somewhat similar to Plato's Allegory of the Cave - the philosopher is someone who climbs out of the cave of ignorance
Japanese version is 井の中の蛙
I think this is the only modern usage where 蛙 is read かわず instead of かえる
碧眼紅毛
Blue eyes and red hair. Describes people of European descent, maybe more specifically people from central Europe. The description sounds like the Irish, but Ireland didn't have influence in East Asia. Perhaps the phrase is describing brown hair, not necessarily the exact same as the English term "redhead".
Also written 紅毛碧眼
Non-Sinitic Idioms
There are idioms in Japan which are borrowed from English but have the structure of a chengyu. What the heck.
一石二鳥（いっせきにちょう）
Calque of "Killing two birds with one stone" (the verb "to kill" is omitted, literally means one stone, two birds (this matches Japanese word order: one stone (INS) two birds (OBJ) kill))