What is the dolphin best known for?

Dolphins are known as the only mammal which lives in water.

This is very suprising that a dolphin looks like a fish rather than a mammal.

It is a mammal because it doesn't have scales nor hair.

Also it feeds young ones with milk. No fish does that. And as you know all fish lays eggs, but the dolphin doesn't. Rather than laying eggs, like all mammals it lays babies.

You can find information about a bat,the only mammal which can really fly in the Question ," Give a few resource Information about a bat ".