Molly

Mollies are small, nonaggressive, community fish with a reputation of being easy to care for. While indeed a top choice for beginners, they are livebearers and are highly hybdrized -- which means there are many varieties, but you also won't  be sure what you are getting. Also, as a brackish fish, there is some debate over how much (if any) salt they should have in their environment. Nevertheless they are a favorite of aquarists. Mollies should get at least one gallon of water per inch (though more is always better), and can grow to about 4 inches long. They live 3-5 years and are ominvores that will eat flakes supplementd with live and freeze dried food.