1. There's something fishy about this
Seeming bad or dishonest; If something is very strange or suspicious.
There’s something very fishy about him.
2. A big fish in a small pond
Someone who is important in or who has influence over a very small area.
Mr. Bean is a big fish in a small pond. Lots of people like him in the town.
3. A fish out of water
Feeling uncomfortable because you feel you do not belong in a place or situation.
I feel like a fish out of water in this new place, I don’t know anyone here.