An alligator has a broad snout but a crocodile has a narrow snout.
> Please use the article "a" if you are talking about a single object.

Also, an alligator is brownish but a crocodile is greenish.> Be mindful of your spelling.

And, An alligator is more an aggressive than a crocodile.> Do not begin a sentence with the word "AND." We add a be-verb such as "am,is,are" before our adjective.