Any yarn and proper hook could be used as long as you get a tight gauge. Unicorn shown used Red Heart Super Saver-less than one large skein (14 oz) of white and scraps of all of the contrasting colors. You will also need poly-fill to stuff your unicorn as well as a stitch marker (I used a scrap piece of contrasting yarn) and a tapestry needle for sewing in ends and sewing pieces together.

Stitches and techniques used:
Magic Ring (there is a photo tutorial if you are not familiar with this method)
slip stitch
decrease (defined in pattern)
chain
single crochet

This is a fairly easy pattern, an adventurous beginner should have no trouble with this pattern.

There is a fair amount of sewing pieces together (the arms, ears, horn, legs, head, mane and tail pieces must all be sewn together). If this makes you cringe, this may not be the pattern for you.

Gauge is not important, so long as you have a tight gauge so it looks nice when stuffed. I used Red Heart Super Saver and had a fairly tight gauge these were my unicorn’s measuremetns:
Finished unicorn is about 16 inches tall (does NOT stand on its own) from the bottom of the feet to the top of the horn. When sitting (unicorn does sit on its own with a little manipulation) it is about 10 inches from its bottom to the tip of the horn.