Most people consider it a whale.
...They tend to be found around Miami, Florida. ;-)
Btw did you know crocodilians are more closely related to birds than other reptiles since birds are technically reptiles (though taxonomy labeling leaves that out because its a very basic system.)
The most common animal on earth is probably a type of insect noone has ever heard about.
Something can live in large numbers and hardly be noticed, and ander touched on the other half of the explanation, being noticed and being made popular to the big crowds is something else aswell.
I AM SO SORRY DON'T KILL ME