Do you really need to make it yourself?  If you've never done this kind of thing, it might be difficult to make a recognizable horse pinata.  Especially if you are pressed for time.

You might consider buying one like this:  http://www.partywedding.com/viewprod.asp?prodID=3097

Or google unicorn pinata or horse pinata.

Sue

Rozani's tutorial on pinata making should help you: http://www.papiermache.co.uk/exec/cms-d … iew/id-18/

You could draw a simple horse shape onto a piece of cardboard and use this as a guide to the shape of your pinata, then follow Rozani's instructions.

Don't make the legs too thin - it will only need to represent a horse and not be anatomically correct. You could use streamers for the mane and the tail.

Hope it goes OK.