This is entitled Mountain Monster, by Chris McMaho. I find this pretty creative and a bit hilarious. Talk about appropriating art to make art. Ha!
"Artists Chris McMahon and Thyrza Segal have each added a fantastic collection of monsters to dull landscape paintings that they found at various yard sales and thrift stores. Prints of the enhanced paintings by Thyrza (Etsy) and Chris (deviantART) are available to purchase online." (from Laughing Squid)
Chris McMahon's collection is here. Thyrza Segal's is here. The later's gallery is particularly entertaining, since she includes the before and after. (Beware! Zombies, too!)