According to the Mistress, the Anharrans are notoriously and irrationally blood-thirsty, known for feasting on the still-living flesh of all they encountered. For instance, it was the cultural norm for punishing disrespect with evisceration.
There were two types of Anharrans: giant gorillas-like demons with fur and heads resembling lampreys, and goat-like demons.
The Soul Glutton and The Mistress opened a portal to their world to trap Buffy Summers, bringing the Anharran army over to this world. Kerberon was killed when he attacked Dawn due to her status as the key. Impressed by this, the demons choose her as their goddess-king. Under her rule, they adopted a peaceful lifestyle and learnt how to construct stone houses, indoor plumbing and even a theater.They also made their own rendition of The Princess Bride, a movie which Dawn was a fan of.