They are somewhat large, possessing shaggy 'fur' around their chitinous bodies as well as mandibles, faceted eyes, and spikes on their arms ending in spiky pincer-like hands. Due to their evolutionary ancestry, the Pa'uyk tend to be comfortable in small alcoves. Their living quarters tend to be covered in items to form a small 'alcove'-like cave where they sleep. Their attitude towards rules is that they're meant to be broken, and they were not above using underhanded actions such as cheating and gambling.
They are a naturally aggressive species which channel their anger through the use of insults which is seen as common behaviour among their kind. Concepts such as courtesy and polite behaviour are seen as abhorrent as well as insulting. As such behaviour is not present in Pa'uyk culture, most members of this species tend to view people who are 'polite' with suspicion as in their culture such people are attempting to kill them.
Unfortunately, this constant aggressive behaviour leads to many battles that are devastating to the Pa'uyk civilization. Planets, fleet and thousands of lives are lost in these conflicts with even planets being destroyed. Their recorded history has noted that the species has almost destroyed itself at least sixty three times in the past. However, the true extent of their wars is not truely known as during these empire-wide battles, historical records tend to be destroyed as well. As befits their nature, Pa'uyk starships tend to be heavily armed as well as possess cloaking technology.
By the time of the Heran Crisis, the Pa'uyk began a research project into better ways in handling this problem before they destroy themselves. This project was handled by 'exchange officer' Doctor K'Sah who studied Klingon security officer Worf and his species concept of honor. He was later picked up by Cpuld, captain of the Throatcutter. (TNG novel: Infiltrator)