I read somewhere on here about someone who had created a sushi costume for a pug, and that link is dead even if you register for the site, so I here's my own version! (Success, a pic!)
Thanks to my sweet little Washy dude for being such a good sport about modelling
I took a free vest pattern from somewhere by doing a google image search, then just added. The salmon has the fat stripes just from a short but wide zig zag, and that got put over some foam and sewed on. The rice grains are actually packing peanuts - I highly recommend finding some of those figure eight type peanuts, taking the ones that don't have holes in them, then cutting them in half to sew on. The type of styrofoam for those peanuts is much less crumbly than the others I tried, and vaguely rice shaped when cut.
I didn't get the chance to finish putting on the rice (the contest was starting! what a stage mom I am)and I think there ought to be some type of piece around the shoulder just to make it look more like the right shape, but other than that I was quite pleased with the results, and he won first place in the costume contest! What shall he be next year???