A phrase added after any adjective to make it stronger.

Perhaps started by people trying to be less vulgar than using "as fuck" or "as shit", but still wanting to use a dirty word.

The resulting phrase doesn't have to have anything to do with testicles or their qualities; it's almost better when it's very un-ball-like, because it makes other people stop and think how your phrase doesn't make sense.

Internet persona(s) who happens to follow you and you happen to follow them back and maintain communication with and have a mutual liking for eachother whether it be friendship wise, etc. (Mutuals if more than one mutual)

To the most extreme degree.

To an extreme degree, especially with regard to temperature. Likely derives from the phrase "cold enough to freeze the balls off a brass monkey," which itself dates back to the 19th century.