A java mod that introduces a new mob: The Stalker.
The Stalker is a dweller-type mob that spawns in groups. It will remain slow until it touches a player or gets hurt. When that happens, it will roar and attack the target rapidly. That behavior is the reason as to why it's called the Stalker.
The joke part comes from it's difference with the other dwellers, as it is their obsession with campfires. What this means is that, if you have any campfires in your base, you could have ten of these guys dancing around it.
These guys love campfires so much that they have two structures made specifically for them:
-The Ritual Pyramid.
-The mating grounds, where a large population of Stalkers is concentrated.
You will see the Stalkers moving into these tructures and start roaring/dancing around the fire. After a period of time they will break the campfires and start hunting until they find another structure.