A "Badge" is a valued flair denoted by a small pixel icon that is located at the top right hand-side of a users page. They are to recognise small achievements, participations and some site easter eggs. The most common badge is the "Llama" badge, which can be exchanged to Deviants at no cost whatsoever. Llama badges have been featured throughout the site similar to the mascot Fella. Super Llama is a badge rank and it is also Fella's sidekick.
You can only receive 100,000 llama badges, but there is no limit to how many you can give. However, sending too many at one time can cause problems and cause Deviants to trip spam filters. Deviants are limited to only receiving twenty cake badges and afterwards can receive no more. These come at a cost of 80 Points, and can be given to any Deviant who has not already reached the limit.
Llama badges can also be sold as a bribe, normally only sold through the Deviant art system for around 1 Point, but people give badges for the amount any way.
The Paranoid badge is also a site easter egg and can be obtained by any one by attempting to pre-order at this []. Please note you cannot actually buy the hat! But attempting would give you the badge, which you sadly cannot anymore.
Also check List of badges