Here are two you are welcome to use:
My buddy Pat tore the first one out of an old issue of Juxtapoz or something similar. That second one comes from a nifty one-page comic published in Heavy Metal in the 90's. Click to embiggen it:Now that I think about it, that barfing T-Rex would make a pretty cool avatar as well.
Wednesday Comics: The Clandestinauts
5 hours ago