This is a very cute mini snowman! You can make it any size by changing the yarn weight and hook size but with worsted weight yarn and a 4.0 mm hook it is about 18 cm (7 in) tall (however, the hat can be any size you want).
For colors, you need white, brown, orange, black, and colors for the hat and scarf. The snowman is made from six pieces- the body, 2 arms, nose, hat, and scarf.
The scarf can be crocheted using whatever stitch you like, however I used a lucet tool to make the scarf.