Here is a way I came up with a while ago and it works for what you want. 
Here is how to do it. You need to add a new pet to the pet dbase, just do it in Navcat. Make sure to create the pet as an NPC in your dbase. Then use the following...
$client->MakePet(null, DBPetName, "Pet Name");
DBPetName is the pet dbase name for the new pet
"Pet Name" is the of the pet the player will get.
	Code:
	sub EVENT_SAY {
if ($text=~/hail/i) {
quest::say ("I will be your pet"); 
$client->MakePet(null, TestPet, "Light Elemental");
}
}
 This summons a pet called "Light Elemental"
Kayen
GM Stormhaven