We made 4 legged stilt costumes for halloween. We call them stilt spirits for lack of a better name. Mine has extra large medical crutches on the arms which make it really great for your back. Very comfy! Circus peg stilts for the legs (custom made by thespinsterz.com). Garen used dry wall stilts for his legs. They are mainly made of upholstery foam (it comes in a big roll for chair cushions) and fabric. Surprisingly easy to make.
We were inspired by the Frouds who made the Landstriders in the Dark Crystal. They have seen them in person and love them! We were also inspired by Miyazaki.
Feel free to ask any questions if you're making a similar costume and need advice. Video belongs to me. Music is "The Ghost Inside" which belongs to Broken Bells. Great song.