Haven't done of of these in a while -- plain ol' pencil image...thing (technically pencil + charcoal pencil, but you get the idea), though I did tweak the colors in Photoshop just because. Drawn on a brown paper bag, thus the texture.

Yeah, not the most accurate rendition of a snake, but I was doing this by memory, same as the dove. Why these two? Feel free to guess, though I'm guessing only a handful of you will ever really figure it out :P