This spell can be gotten in EK. It is on the the far east side of the zone, in a little village down by the water. The merchant that sells it stands off by herself along the shore.
On another not I truly love this spell my pet het for about 50 each time. Just buff him up with an Infusion of spirits along with your other stat buffs and gtg. This pet can solo Hill giants with ease, even if you dont slow the giant. Mind you I always haste my pet, buff, and get my pet procing weapons and a muzzle from the bazaar. This is an understanding we have. If I am going to sit back and look for another giant to pull, then he has to have proper equipment. Follow these rules and your pet will not let you down. Oh yea the muzzle and the procing weapons run about 7 to 10pp in the bazaar. They are not the sword like feather looking weapons(those wont proc for him, to low lvl). These are like hands of something. They look like little red circles with white spikes going all the way around them.