I found this macro on my hunter, its really simple, i think it's
/script PetPassiveMode();
/cast Freezing Trap
Make this macro, put it on your bars. Now, when your in pvp combat, and say a warrior is beating on you, have your pet out, spam it a few times, and BAM! Warrior frozen. Only works in pvp not pve and dont think it works for 1.12 so use it while you can! Also works with frost trap.