[NatedogEZ]

zone_controller.pl

This npc can track the deaths of any NPC so no need for signals and such

my $kill_count_69420 = 0;

sub EVENT_DEATH_ZONE {
	if ($killed_npc_id == 69420) { #NPCID of whatever
		if ($kill_count_69420 < 20) {
			$kill_count_69420++;
		} else {
			$kill_count_69420 = 0;
			#We hit 20~ spawn something or whatever
		}
	}
}

Edit: just noticed how old the OP is on this.. but anyways this is a nice way for anyone who sees it :P