Step 1. Concept
The initial sketch and a quick 20 min color/light study. I had a pretty good idea of what colors I wanted him to have so this was a pretty fast process. I grew up always having some sort of freshwater tank in the house and always loved the colorful catfish-type breeds you could get. At first I played around with the idea of him having more muddy colors like a real catfish, but decided that if he was an NPC you were trying to find underwater from a distance, than I wanted you to be able to see specs of color from afar. I didn't want him to totally pop out, but I didn't want him to blend into a watery blue blur.
2. Next I did a very basic body sculpt in Zbrush(render from Maromset):
After I got the model where I wanted it to be geo-wise, I built out all the extra details and decorations.
I cut the main body in half, and cut UV seams for how I wanted the geo laid out:
Once I had all the geo laid out I went ahead and started painting in the texture. I started with a flat color laid over the normal map I baked out from the original zbrush sculpt:
From start to finish this guy took me two weeks, working 2-3 hours a day.
I feel like I'm leaving out a million in-between steps but these are the big chunks of process I used to create this guy. I ended up creating a full map set for him, for more professional renders outside of what was required for the Blizzard contest. The Blizzard version was only rendered out with a diffuse map. This version has a diffuse, spec, normal, and emissive map applied but the same polycount.
Maya 2014 student edition