Glad to know I'm not the only one! I've got this betta shirt with a red background and white design: Betta Fish | Men's T-Shirt by American Apparel designed by ibisdesigns | Spreadshirt | ID: 3474845
(actually looking at it again, I have that design not that exact shirt). There is another betta shirt on that website that I want, too. I don't have a picture of me in it, tho. At least I don't think so and don't feel like digging through my photography library right now.
I love the design on yours, Theraggy. Where did you buy it?