From Valve Developer Community
- Fired when an NPC is spawned. The activator is the NPC, and the string is the name of the NPC.
- Fired when the spawned is exhausted (all children have been spawned).
- Fired when the spawner is exhausted (all children have been spawned) and all spawned children have died.
- Fired when all spawned children have died. This does not mean the spawned is exhausted, so a new child may be spawned any time after this (unless the maker is disabled).
- These outputs each fire in response to the firing of the like-numbered
FireUser4Input; see User Inputs and Outputs.
- This output fires when the entity is killed and removed from the game.