Nurse

This is the most adorable little costume, It is so sweet a bet they did well in their costume class.

Pikachu

Bumble Bee

Phantom of the opera

Elvis

Here Is a Great Elvis Costume, The horse has actually been painted pink! and has their own band of girls in poodle skirts following. If you wish to try this you need to get some water based washable paint (maybe child friendly craft paint) and test a small square a few days before your contest to check for reactions. I would suggest doing a bit or research to find out what products other people have used .IMPORTANT!: If in any doubt don't use!

Peter Pan & Tinkerbell

A peter pan themed costume.
This is really simple and you don't need to get your horse used to anything except a hat
All it involves is making a green rug which can be as simple or as complex as you like, a hat for your horse and a tinkerbell/peterpan costume for yourself (of course it can be the other way round if you wish)

Try it and send me your pics!

Medival Barding straps

I Found this costume whilst on ebay, the seller didn't seem to be a costume maker so i didn't save them