Velghastrials are Ghasts with magical abilities, which play roles of pack leaders.
Background
Taking shelter in various mountain caves, ghasts are highly territorial creatures who live together in packs. If they have sufficient numbers, they will drive away or even kill those who encroach on their territory with malicious fervor.
While they are cunning and have a basic understanding of cooperation, ghasts aren't considered truly intelligent beings, as they are incapable of speech. Despite this, some ghasts have demonstrated an aptitude for magic. Called velghastrial, these ghasts quickly rise up in the pack's social structure, and often become its leader.