What are butterfly mollies? i saw them at petco?

Have you ever had guppies? Mollies are fish that breed quick and easy like guppies, they're pretty and they don't require any extra attention too. You just feed them and keep their tank clean. They are very good in community tanks and they grow pretty fast. Mollies actually can't get that big, about 2" at most I believe. Also, I wouldn't say they need to be in big groups but I would definatly recomend that you have atleast 3. :)