I think the Laughing Cow Disease is a contagious disease! (and far better than the mad cow disease of course). I like John's cow additions to his envelope!
It's a crazy envelope. It made me smile the whole morning... :D
By the way, I found a crazy cow mail art project (from 2012), there's even a Mona Cowsa among the contributions, see here: http://crazy-cow-gallery.blogspot.nl/
Glad to see the little felt cow survived I wondered if she might get slaughtered in the post!
It's amazing, but she did. She arrived really happy because of the trip.