According to human demonologists, he was described as ruling over thirty legions and "as having the ability to turn any man into a bird." and "to make men subtle in all things pertaining to Mensuration, among other things".
The Peacock wasn't a warrior, and preferred diplomacy and measure, and often was tasked to try to ease the tensions between demon lords of the Dark Legion, being said to be very cunning in his dealings. The origin of the ability to turn men into birds, may be due to his own preference of bird-like vessels for him and his soul shards.
In his court, there was an academy centered around study of geometry and mathematics, along with magic and astronomy.
One of his preferred forms was of a Peacock, but as well could take the form of a man.