I think the easiest way to do this is a quest:
	Code:
	sub EVENT_SPAWN {
	quest::settimer(1,1);
}
sub EVENT_TIMER {
	if($timer eq "1") {
		$npc->SetAppearance(1);
		quest::stoptimer(1);
	}
}
 This is taken from the Kerafyrm script to make he/she/it go to sleep on spawning. I'm not sure if there are any issues with just executing it under EVENT_SPAWN, but you can also try that:
	Code:
	sub EVENT_SPAWN {
	$npc->SetAppearance(1);
}
 I'm sure there is a list somewhere of the different appearances, but I can't find any offhand.
Hope this helps.