Overview
this guide will help anybody that needs help regarding spawning in npcs within half life or half life source.
Required things before starting
Make sure you have sv_cheats enabled. You can do this by pressing ` or ~ on your keyboard then typing in sv_cheats_1 in the console. If the console does not show up go to your settings and then enable the console.
How to spawn in NPCS
Now, after turning on sv_cheats, you must then go back to the console and type in: give (then the NPC name you want to spawn in) for example, to spawn a Human Grunt, type in give monster_human_grunt. The names of npcs that you can spawn in that I am aware of are:
(PS. remember to noclip while spawning npcs as they will spawn inside of you.)
monster_human_grunt
monster_alien_slave
monster_scientist
monster_barney
monster_headcrab
monster_zombie
monster_alien_grunt
monster_houndeye
Other “helpful” commands
While spawning in npcs, for hostile ones to not shoot at you, type in notarget into the console. Remember to noclip while spawning in NPCs.