Because the artist plans on creating a mold, he is using Plasteline clay, which is an oil-based clay which does not harden. The Plasteline figure will be discarded after casting. The author says: "I'm not narrowing down the materials too much. The actual sculpting medium you use is entirely up to you, and this tutorial will focus on my process more than anything. I sculpt using many materials- polymer clay, air-dry stoneware clay, wax, plasteline, paper clay, and epoxy putty- but for all of them the techniques used vary little. This tutorial centers around designing, sculpting, molding, casting and finishing a piece."
Because of the fragile legs and other detail in this sculpture, I would recommend using a stone clay like LaDoll or Creative Paperclay for a OOAK sculpt. The soft clays like Hearty and ClayCraft usually don't work well with the methods shown in this tutorial. Cold porcelain may also be too soft...depends on your recipe! You'll also run into problems if you use one of the inexpensive 'school grade' clays....believe me!
There's a number of great tips in this tutorial, such as using Jewel-It glue to coat the armature wire to create a tacky surface which the clay can adhere to. The author attaches poles to the raised legs which are intended to act as air vents after the model is molded, however, this is also a good way to support the legs until they dry.
You can skip the molding process and can skip the resin casting for the splash...but don't miss scrolling down the page to the painting and finishing section. Author uses pastel chalks that he has ground to powder for painting the finished figure. He also uses acrylics to paint eyes and enamel for gold horn & hooves. A mix of wool and mohair creates the mane & tail.