Rare Spawns
From Hack/Mine Wiki
Rare Spawns
Rare Spawns are variants of normal mobs which are harder to kill but provide a guaranteed loot drop. They are about 4 times as strong as their normal counterparts. High levels can be dangerous to a low leveled player.Rare Spawns are usually the same size as the normal mob of their type, with the exception of slimes, which can grow 1, or very rarely 2-3 tiers above normal slimes. They feature alternate coloring, and also have a unique name displayed in their health bar, consisting of a randomly generated prefix and suffix not unlike that of magical items. Along with more health, they are much stronger, and can leave a sizable dent in a rather careless player.