Nemo's looks:
"For the striping and the Nemo-likeness, I tried to do a simple knit version of the Nemo picture I found at  vistawallpapers

The fins:
"The side fins were made by casting on 4 or so stitches and then doing a series of short rows (wrap and turn) until the desired length. I made 2 at the same time and then cast off in black yarn using the 3-needle bind off. Repeat and then sew the sides together and attached to the body.
The body fins were made similarly; except I picked up stitches directly from the body to ensure the orange stayed in the orange section. "

Nemo's tail: 
"The tail fin was made by narrowing before the fin section in the round and then switching to straight’s – increasing at the ends until it look proportional in size, and then a few short rows on each end to make it look like a fin. Followed like the fins by casting off in black yarn using 3-needle bind off and then sewing the opening together. "

Want to see more Nemo's, with or without 'lucky fin'? Visit Ravelry's project pages.