Breyer's 2010 Treasure Hunt models are a trio of draft horses, one for each of three seasons (Spring, Summer, and Fall).  As a gift for purchasing all three of the Treasure Hunt models, mail your UPC code to Breyer and they will send you a free fourth model, "Winter."

The model collecting community is going collectively gaga over Winter!  

The 2010 Treasure Hunt models use the popular Winter Song mold, a Shire stallion which was created by Kathleen Moody in 2007.  This mold has been re-issued many times since then, and has frequently been used as a special model for events like the BreyerFest Velvet Rope and Tent Special.

Spring: A chestnut, with four white stockings and a big white blaze.
Summer: A classic tobiano pinto.
Fall: A bay, with three white stockings and a white star.
Winter: At least one user has received hers, and reports that it is a leopard Appaloosa.  Check out her pics!

One thing that makes this treasure hunt an interesting challenge is that the first three models are also being shipped as glossies!  There are actually two sets of Treasure Hunt horses: matte (called "chalkies" by collectors) and glossy.  Although most of the Treasure Hunt models are matte, there is a second line of glossies which you can hunt for.

I found one person online who had managed to collect all six of the Treasure Hunt models - one set in matte, and one set in glossy!  You can check out her awesome pictures here on the MLPArena forums.

Last year's Breyer Treasure Hunt had up to 10 different variations on the "Fun Foal" mold.  The Fun Foals Treasure Hunt for 2009 involved two stallions (a jumping palomino and a dapple gray mustang) and two mare molds (a dappled liver chestnut Appaloosa, and a big red roan draft horse) .  If you purchased one stallion and one mare, you could send in the UPC codes and get a free Fun Foal.   

One fun thing Breyer did with the Fun Foals treasure hunt was to send you a foal which resulted from the combination of genetics of the dam and sire that you sent in.  So if you sent in the UPC codes for Wixom (the red roan draft mare) and the Jumping Horse, you might a red roan foal.  Obviously he would have taken after his dam, but other Fun Foals took after their sires.  A very few collectors even received an extra special prize - a pair of twins!  

Without seeing more of the Winter models, it's difficult to know if Breyer is planning anything similar.  Although the leopard appaloosa could be considered a natural progression from the pinto.  I wonder if all four horses are meant to be brothers, in which case, what must their dam and sire look like?  Breyer had fun playing with the genetics of the Fun Foals - but it's hard to say if they are doing anything similar with this year's Treasure Hunt models.