Black Molly

Question
I have a Black Molly which has a very strange orb growing from their head, close to the eye. I have had this fish for several years, and have never seen anything like this before.  My tank is 35 gal and only has a pleco and one large goldfish besides the Molly. I hope you can help me identify what this is.
Thank You

Answer
Carol,
It could be a tumor growth, but hard to tell without a picture. One thing I noticed is that you have a goldfish with a molly. The goldfish is a cold water fish and the molly is a warm water fish. A molly is a brackish fish, which means it needs to have some salt in its water. The two should not be in the same tank. If you can, upload a picture so that I can be better informed to help you.