NPC Spawner

I’m not sure if I’m the right section as i don’t do this stuff normally but anyway, lets cut to the chase, If you have been on the Gmod Toybox you may have seen the Zombie spawner. Now, Ive been wanting to to know how they make/do that, so that possibly i can make my own personal ones with NPCs of my choice, or maybe even contribute to the toybox. So basically my question is, does anybody know a link they could direct me to or know someone or know themselves how to do this?

With this, http://www.garrysmod.org/downloads/?a=view&id=84684 you can select npcs and then wire them up to a timer when they should spawn, or you can press num keys to manually spawn them.

Thats something like it but (and im assuming the Spawner i was talking about is an entity) i want it as that so i could have it in my handy entity tab.

You click the npc and it turns into a spawner( a transparent npc ) that you can move around and even weld to things. You can’t really have a SENT with a big list of npcs and choose from the SENT. It would have to be done through a STOOL, this is probably as easy as it gets and its already finished and working.

Alright thanks anyway.