This video explains how to fold an origami goldfish using a single sided solid colored sheet of paper of size 6".
Ancella Simoes is the author of the Origamiancy Blog and creator of all the Origamiancy origami tutorial videos on WonderHowTo. From Ancella's site:
"I fell under the spell of Origami early 2008 and have come to love folding new models and designs, so much so that it is now one of my favorite pastimes! Generally, I look up diagrams on the Internet, but I also own a few, very good, Origami books, which come in real handy."
This video demonstrates Ancella's technique for folding an origami goldfish.