The Demon by Michael Powell

http://michaelpowellart.blogspot.com/

Demon by Jess Kirby

I did some research on Etrigan and it said his creator was a Kirby, so I thought I'd add the Kirby in for good measure!
(seriously though, this was just a quick sketch. I was so glad that I finally came up with an idea!  I think I'll colour this one in and re post later.)

Baby Etrigan by Eryck Webb

From the Justice League Unlimited episode "Kid's Stuff"

http://ewgraphics.deviantart.com/