蟷螂の斧
(Tourou no ono; “The mantis’ axe”)
Definition:
The weak standing up to the strong, often with the implication that they didn’t really think through how great the difference in strength would be. A praying mantis that senses threat will rear up and wave its axe-like arms, even at foes who are many times larger than itself.
Breakdown:
This simple noun phrases uses the associative particle の (no) to link the noun 蟷螂 (tourou, a rare Chinese-style-pronunciation term for what is more commonly known as kamakiri), “praying mantis,” and the noun 斧 (ono), “axe.”
Notes:
Tourou may also be written as 螳螂. More importantly, the outsize foe being faced may be specified: 蟷螂が斧を以て隆車に向かう – note the change in particles – (Tourou ga ono wo motte ryuusha ni mukau), “The mantis, holding an axe, faces a [large vehicle].”
(This is kind of tricky. The longer version may have fallen out of favor in part because 隆車 is simply not a Japanese word. A little searching returned results for modern motorbikes, cars, and ATVs… in Chinese. My sources say that the 隆車 is some kind of large wheeled vehicle, but anything more specific, or a proper English translation, is beyond the scope of this post.)
Anyway, the image of a praying mantis rearing and showing its hooks to an onrushing cart is a pretty evocative image of standing up to someone more powerful than oneself. Here’s to hoping it works out alright.
This saying comes to us from the Han shi waizhuan (韓詩外伝, in Japanese Kanshi gaiden), a sort of midrash to the Classic of Poetry.

Rar!
Example sentence:
「かつて、金持ちに立ち向かう者は僅かの間蟷螂の斧を振るってから潰される嫌いがあった。ああいう時代にはもう絶対に戻りたくない」
(“Katsute, kanemochi ni tachimukau mono wa wazuka no aida tourou no ono wo furutte kara tsubusareru kirai ga atta. Aa iu jidai ni wa mou zettai ni modoritakunai.”)
[“There used to be this awful tendency that anyone who stood up to the rich would stand against impossible odds and then be crushed. The last thing I want is to return to those times like that.”]