In certain situations, depending on your pet and the attacks your enemy casts, your pet will help you gain power or cast a shield.
I have an Ancient Storm Cat, that may cast Storm Ward. That means that if I'm facing a Storm type enemy, and my health is running low, my pet will cast Storm shields in the middle of a turn. It may turn you around in a tight match.
there isnt a pet that will just randomly cast charm on you. there are pets that have cards with them that can be charms and, when the pet is equipped, will put a charm in the sideboard of deck that improves attack.
I have 2 fire serpents now that have "Firetrap" "May cast (fire) ward" ...
Can an admin please god answer this question orginally posted, because from all accounts this does not seem to be working AT ALL.
Some people have (School) Aura "May cast (school) ward" that is a shield, but I'm assuming that the traps were supposed to be debuffs to the enemies, but from everything I've read it doesn't appear to be working.