What about a pet that buffs your power?
Maybe the pet boost your stats, help you flying or teach you an special combianted technique.
Also, if beam struggling is added to the game, it could help you.
But keep in mind they are all theorys based on others MMORPG. There are little posibilities in having pets on DBO.
i don't think there should be any pets since lets face it your not gonna see Goku fight when there is a puppy near him is he -_- and lol only pet there would be is Ikurus ( Gohans baby dragon) and that just dances lol
but i like the idea just shame no pets that could actually fight along side with you