Amigurumi is an amazing style of crochet that allows the designer to shape and form yarn into a sturdy and dense fabric. Ideally Amigurumi is "cute" and/or "tiny" animals but the name has become more widespread. With some basic knowledge of crochet, including single crochet, increasing and decreasing anyone can shape the wildest creatures.
It's good fun making these creatures as I tend not to write anything down or follow a pattern. I read what the fabric is doing as I create each stitch and base the next stitch/row on the happenings of the row below. Isaac, the little boy who designed this monster has two older sisters and I bet when they see how cool his new toy is they'll design one of their own!