For Halloween 2015, my son requested to be Dr. Zoidberg. The cool part about this character is, his face is visually easy to construct which gave me the idea to knit a child sized ski mask and slapped on a half 4 fingered glove. I already knew my son's size and did not bother using any pattern in particular.
I ended up knitting a breathing hole that's hidden under the space alien face tentacle thingy. My mask is also two pieces I've sewed together, the pattern is a one piece. For yarn, I've used boring ol' Red Heart, coral color.