For those unfamiliar with the way lost animals in FarmVille work, the Groovy Cow may show up randomly as a pop-up while you have the game loaded. You’ll be able to either ignore the cow, thus ending the “event,” or click on “Share” to post a news item to your wall asking your friends for help in adopting this lost animal.
Once you do, your friends will see a posting like the one below, and will be able to click on the “Adopt the Groovy Cow” link to be taken to a confirmation page about the adoption. The cow will then show up in their gift box the next time they load the game.
To get your own Groovy Cow for your own farm, this means that you’ll have to keep a close eye on your news feed to see if you can spot any lost cows that your friends have posted about. Head over to the game’s page to see if a Groovy Cow will wander onto your farm.