Yes, you can buy a companion for any of your horses or ponies.
You click sales, select the species "pony", find one you like and buy it!
You can buy one from the "Sales" page.
Buy one off of auctions or get one in a card pack.
the comanions no longer exist on howrse
You can no longer buy companions for your horses as of Summer 2012. Now you can only buy horses that already have a companion with them.
Is Bella your howrse? First, you need to buy a companion for Bella, and then click on it and select the amount of time you want to play with her.
Only one person has a Quarter Pony, their username is technow.I also have one. My name is DrewDat-WhoDat but you can buy them.
Its a companion!
No.
There are currently no available promotional codes for Howrse.
You must use a Harmony Pack on your horse in order for you to customize its companion ;) applehorse1 on howrse has answered this See ya around ;)
Companions were sold on Howrse for a limited time, sort of like the Lottery; its a short phase. Only now can you buy rare horses with companions instead of buying companions to put on horses. Hopefully Howrse will bring them back