Youtube user TheOrigamiVoyueur has itself received in this time-lapse, as he folds a koi from a dollar bill. Simply an amazing transformation of a piece of paper towards a three-dimensional fish. Impressive!

Nails
Folding Won Park's Dollar Koi

If you want to imitate the, available here the first of the eight parts of the manual.

Nails
Won Park Koi Instructional Pt. 1.wmv