After logging on to a vanilla server on 13w18c if you get on a horse then log off the server then back on, a second horse of the exact same kind wearing the exact same things the first horse was wearing will appear. You can do this as many times as you want and have unlimited horses with diamond armor and saddles as long as you create the first horse
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Duplicate of MC-13737, please use the search function to see if your bug has already been submitted. Currently over 55% of tickets are being closed as duplicate.