His face reminds me on the many similar crafted faces when I visited Tuscany a long time ago and we went to a little hill-town named "Orvieto".

There we searched for the church in the middle of it and found it in the evening all lit up as to make the art visible to visitors. On the bottom of the church's building there were many creatures carved in stone who suffered a great deal in hell. They had this agonizing expressions on their faces, exactly like your pantomime type here!

What is he spilling out? What does the green slime contain?

P.S. is it because of the contrast, the oh so tidy houses, bricks and squares surrounding him?