Monstermakers

The yellow button, when pressed, will spawn one barney. It won't do anything if there is already a barney in the room. This is because of the "Max live children" property of the monstermaker called "makebarney" (set to '1').

The 'cyclic' flag means that it will try and spawn a monster when it is triggered, as opposed to trigger once for on and again to turn the spawning off.

The red button turns on and off the grunt spawning. They will spawn every five seconds if there is room (i.e. the 'pad' is free).

For more information, look at the HL Entity Guide, Misc/monstermakers.