It is just like English sayings and phrases, there are Japanese sayings and phrases as well. It is called [kotowaza ことわざ].

Today’s kotowaza

海老で鯛を釣る　Ebi de tai o tsuru

Few words for you.

Ebi – a shrimp

Tai – sea bream

A crow imitating a cormorant.

use small fry to catch (a) big fish

Its origin

Fishing for sea bream (an expensive fish) with a little shrimp.

Its meaning

Getting a big thing with a small thing

arigato