How do I throw a snowball? Where to get them? What is that achievement for?

You can buy snowballs here. You throw snowballs here.

I got the achievements in about three days during the current 5 for 1 event. You can get a sticker, a trading card and a book from completing all tiers. In one browser window, I opened the Avalanche Emporium to buy snowballs and made the window 1/2 size. In another browser window, I opened The Snowtapult and made the window 1/2 size. I placed each of the browser windows side by side, so they could both be seen at the same time. I bought the exact same type of snowball each time. The first time, I typed my name in The Snowtapult to launch it at myself. Once the snowball was launched at me, I bought another snowball. Then I just refreshed the "launched page" without having to select another snowball. It went by pretty quickly! There is a five second delay between launching snowballs, so sometimes I'd buy two snowballs before launching another. Good luck!

Ooh! Thanks so much! I'll try that!