Pinterest. I love you. You gave me this:
This is a DIY T-shirt project from Martha Stewart. Cool design, right?
Take a look at the Tools and Materials List. First thing: whole fish or fish replica.
First How-To Step: Generously ink fish.
What?
I like how she gives you a template for the hook, though.
I remember watching her make this on her show. Kenan Thompson was her assistant. It was a very good day. :)