[Striat]

You were calling for the npc to attack a client, but a client is not returned in a timer (does not check for client interaction!). So, you would have needed to add a $client = $npc->GetHateTop(); or something.

That still doesn't account for the other issue. Try this:

#Nightwhisker Fight

my $adds = undef;

sub EVENT_SPAWN {	#Not really needed.  Was for testing.
	quest::stoptimer("rat_adds");
	my $adds = 0;
	}

sub EVENT_COMBAT {

  if ($combat_state == 0) {
    quest::depopall(2700659);
    quest::depopall(2700660);
    quest::depopall(2700661);
    quest::stoptimer("rat_adds");
    quest::stoptimer("rat_agro");
  }

#Replaced event attack with:
  if ($combat_state == 1) {
  quest::stoptimer("rat_adds");
  quest::shout("Rats of Dreadsire, I call upon you! Come to my aid!");
  quest::settimer("rat_adds",10);
  }

}


sub EVENT_TIMER {

  if ($timer eq "rat_adds") {
    quest::stoptimer("rat_adds");

#the big chunk of change
for($adds = 0; $adds < 10; $adds++) {
   	quest::spawn2(quest::ChooseRandom(2700659,2700660,2700661),0,0, $x, $y, $z, 0);
	sethate();
	}
    	quest::say("Come! Come! Rid these halls of the humaniods!");
	$adds = 0;
    	quest::settimer("rat_adds",10); }
    
}


sub EVENT_DEATH {

$timestamp = localtime(time);

  quest::depopall(2700659);
  quest::depopall(2700660);
  quest::depopall(2700661);
  quest::stoptimer("rat_adds");
  quest::shout2("SQUEEEEEEEK!");
  quest::write("bossdeaths.txt","[$timestamp]:Nightwhisker was killed by $name the $class.");

}		

#added routine to process ALL npcs.
sub sethate {
	my $client = $npc->GetHateTop();

my $tiny_rats = $entity_list->GetMobByNpcTypeID(2700659);
my $albino_rats = $entity_list->GetMobByNpcTypeID(2700660);
my $black_rats = $entity_list->GetMobByNpcTypeID(2700661);

    if ($tiny_rats) {
my $hate_tiny_rats = $tiny_rats->CastToNPC();
$hate_tiny_rats->AddToHateList($client, 1); }

    if ($albino_rats) {
my $hate_albino_rats = $albino_rats->CastToNPC();
$hate_albino_rats->AddToHateList($client, 1); }

    if ($black_rats) {
my $hate_black_rats = $black_rats->CastToNPC();
$hate_black_rats->AddToHateList($client, 1); }

}

Technically, it could still have a problem or two so you could consider using an array and processing a loop for each npcspawn. While it is *technically* possible to run into a problem, you won't run into the potential problem with this script. Let me know if it works for you!