I was trying to find a related thread but had no luck, so I really just wanted to share my sorrow with other people who care about bettas.
My family and I were at Petco today, and I typically gravitate straight to the bettas because I'm kind of addicted...heh...
Anyway my mom managed to find a pure white (save for a pale black dot on his dorsal which me think he has actually a marble, but i'm not sure) masked half moon betta. But he had a large black raised spot in the middle of his forehead that looked like a tumor. He seemed healthy otherwise but I didn't want to risk it. (Plus my 5 gallon isn't completely set up yet.)
Here's a picture (sorry it's so terribly blurry I have a reaaaally bad camera on my phone and that's all I had.)
You can kind of see the raised area on his head.
That's all really, has anyone else seen the perfect fish save for some kind of disease or otherwise?