I highly recommend painting a cow. I did one here in Portland, OR and it was a lot of fun - especially the auction party.
I had to work on my cow in the living room because I couldn't get it up the stairs to my studio. Months later and over 3000 tiny oil pastel drawings of dogs, dog bones and dog toys decoupaged onto said cow later, I finally got my living room back.
The final touch on my cow was a big bone bonded to its mouth. I called it "All Beef Dogs".