Hey GM, is the following statement a correct statement? "Not all frogs are amphibious." I am only talking about the statement, not the animal. I say
it is a correct statement.

As a piece of English, the sentence is totally acceptable.

Thank you very much GM, I really appreciate your
help mon ami. Stay cool

Not all but a few called toads

Toads and Frogs are both amphibious. I wrote a story
about a man we called, Frog; and that is why not all
frogs are amphibious.

I think you meant "amphibians", a noun for a kind of animal, most of whose members start out aquatic and end up terrestrial.

"Amphibious" is a adjective I've used and heard used to describe a vehicle which can work both as a boat or on land, like ones the military uses for beach landings, and which are commonly called "ducks", at least in my area, New York State, where we use them to conduct tours.

Here's a mnumonic I invented for this:

"Not all amphibians are amphibious. Some live out all of their lives in the water and never move to live on land."