A Mantis1 Trying to Halt a Chariot
Once a carter was driving his cart, when a mantis jumped out in front of the cart. Raising its forelegs, it tried to obstruct2 the passage of the cart. Of course, it was crushed by one of the wheets.
This idiom is used to mean overrating oneself and trying to do what is beyond one's ability. The result can be nothing but failure.