Ghost

With the effort of training you horse to get used to the sheet flapping around this could be the cheapest most effective halloween horse fancy dress costume as all you need is some sheets.

Though I wouldn't advise doing the 3rd picture in which the horse's head is actually completley covered so the horse is 100% relieing on the rider.

Pony For Sale~ Great With Kids

This has to be on of the easiest fany dress costumes, for the horse all you need is the sign and for the rider dirty clothes and some bandages, a sling if you have one

BoomBox

With a large cardboard box this could be a simple costume as you just need the handler to dress up in everyday clothes, like a hoodie and just paint the box for the horse and cut out parts so the horse can fit in

Pinata

This is a very time consuming although impressive costume, you could use an old sheet and glue strips of tissue paper (maybee to brittle) or thinish material to it and then get a long bit for the tail and legs

Tractor

Space Shuttle

Pink Car

Police Horse

Red Indian

This is a Fairly simple Fancy dress costume, if you horse is the right colour all you need is some feathers, some paint and a costume for the rider

Pink Horses

Breyer Horse

This was the winner of a large collection i found here http://www.horsegroomingsupplies.com/horse-forums/our-state-show-has-best-lead-line-220111.html

Mystery Machine

Herbie

Flintstones

Star Wars ~Darthvader Tie Fighter

Bob The Builder

SuperHorse

I have infact just made myself one of these, I bought 2m^2 of red material which i cut out and made into a cloak for me and the rest into a square for the horse (like an exercise sheet)

I then got 2 pieces of red felt and two of yellow and made the superman logo, one (smaller) which i stuck to a blue t-shirt i bought and the second to a blue lycra horse head and neck hood(if prefered can be tied)

as i already had the lycra hood is cost me under £10 to make yet still looks effective

And if you are really serious you could also make yourself a hat cover/ put a black wig on top, then wear red half chaps (or red long socks over the top) and wear red underwear(or shorts) over blue johdpurs and with the left over material from the logos a belt.

Shrek, Fiona and of course Donkey

Raggedy Ann

Sponge Bob

This is simply a full blue lycra like rug with a green hem sown on it and prehaps some kind of foam shell ontop

the sponge bob outfit can then be hired from any good costume shop

Harry Trotter

Dragon

Bumble Bee

This costume can be as simple as you want to as hard as you want, you could add afew flowers here and ther to your horse or you can make a great rug like this one