MYSTERY GIFT ITEMS...

As of the 18th August update, the mystery gift cannot be placed on the farm using the web client. It immediately opens when the mystery gift is used. The FarmVille iPhone App still requires the player to place the Mystery Gift on the farm before opening it.

Below are items that could be found inside Mystery Gifts.
Animals  

    Black Pig
    Brown Cow
    Brown Squirrel
    Calf
    Chicken
    Chinchilla
    Grey Tabby
    Ossabaw Pig
    Saanens Goat
    Long Tail Duck
    Brown Chicken
    Horse

Trees   
    Almond Tree
    Breadfruit Tree
    Date Tree

    Mandarin Tree
    Olive Tree
    Pomegranate Tree
    Starfruit Tree
    Guava Tree
    Jackfruit Tree
    Banana Tree
    Cashew Tree
    Fig Tree
    Passion Fruit Tree
    Walnut TreeWax Apple Tree
  
Decorations   
    Butterfly
    Owl Statue
    Birdfeeder
    Buffalo Topiary
    Cowprint Stool
    Duck Topiary
    Elegant Topiary
    FarmVille Flag
    Grass Pile
    Greenery
    Hot Air Balloon
    No Raccoon Sign
    Old Bike
    Pinwheels
    Rose Pinwheel
    Windmill
    Flower Bucket
    Lawn Chair
    Elephant Topiary
    Fancy Topiary
    Flower Bike
    Garden Sundial
    Goat Topiary
    Green Pin Wheel
    Lil Yellow Wagon
    No Fox Sign
    No Gopher Sign
    No Crows Sign
    Pink Pin Wheel
    Small Mossrock
    Stone Mailbox
    Stone Planter
    Weather Vane

Vehicle
    Seeder
    Tractor
    Harvestor

OTHERS
ON very rare occasions it contains 1 FV CASH
 

 

    1,000 Farm Coins (ongoing)
    20 Free XP (ongoing)
    Small Can of Fuel (equals 1/5 fuel tank) (ongoing)
    Large Can of Fuel (equals 1 fuel tank)