You can collect them through other people who give you one. When you have enough badges, the "Llama" levels up (kinda). Some people are so die-hard they offer points for those who give them one. Lastly, you can use points to buy attachments for it.
They just...love llamas...these administrators. So, they started allowing the community to hand them out as well. It's interesting how much people love to get them just to have them get spiffier as you get more.
I thought after you got ten, they became super llamas with a cape....at least that's what happened to mine....it's another way of people saying like your stuff, like you....and it's harmless! Enjoy your llama..it doesn't cost to feed it, and it won't leave little messes all over your page!