Ghast
Ghast is a label applied to various creatures in media, mostly undead. In D&D and Pathfinder, ghasts are a more powerful version of ghouls.
Call of Cthulhu
In Lovecraft's Dreamlands setting, ghasts are vaguely humanoid creatures "about the size of a small horse" who live in the "vaults of Zin", in that world's equivalent of the Underdark. These bipedal pack hunters leap on long, hoofed hind legs like kangaroos. They have orange eyes, an excellent sense of smell, and a venomous bite. They are quite aggressive, regularly attacking both ghouls and gugs. Cannibalism is also common. They die if exposed to bright light.
Lovecraft implies that they have somewhere near human intelligence, but are just very primitive. They speak in a language that sounds like guttural coughing.
Their faces are "curiously human despite the absence of a nose, a forehead, and other important particulars."
