Here's where I am with my poison headcrab hat. I have two headcrab hats and wear them to furry cons. I decided to dye one black and make a poison/black headcrab out of it. (The pic on the left is a black headcrab from Half-Life 2, captured with the model viewer.)

But...the dye didn't work. I tried two types of soak dye, and the second time I used a double dose. Didn't do a damn thing, the dye just wouldn't stick. Next I bought some spray-on black cloth dye. As with the soak dye, it initially appeared to work, but as it dried the crab turned brown again.

I next bought several 1-ounce containers of fabric paint, including flat black, gloss black, white, red and some grays. It took a while, but I painted the whole crab flat black and then added white, red, and gloss black (for the fangs).

This is the first time I've tried anything of this nature -- it's only the second time I've used cloth paint, and I've never painted a plushie before. In retrospect, I wish I had seen how much an airbrush paint job would have cost. I spent $20+ on the various dyes and paints and the crab is less flexible than my other one due to the paint. Still, it's not bad. I may touch it up a bit more tomorrow, or just call it done.