Hellhounds typically spawn within the first 6-8 rounds, and then every 5 rounds after that in packs. During a special round, the map will appear to be shrouded in heavy fog, the announcer can be heard saying "Fetch me their souls!", and the ground will shake when the player is spawned. During certain main quest steps or objectives, hellhounds may spawn infinitely or periodically, in which only the ground will shake when spawned.