If you need protection, there are a lot of stall cards
You really have to figure out a way to pick a fight with something that won't outright kill Garruk in order to get him to transform, but that's not always possible
If it does not it will generally run out of gas and either deck itself or just have no more threats or answers
There are lots of different ways to get creatures into your graveyard perhaps youll place them there from your deck with a card like Entomb, discard them from your hand with spells like Faithless Looting, sacrifice them through an outlet like Ashnods Altar, or simply allow them to die over the course of normal gameplay
You could toss into an equipment brew that includes this to fetch out an equipment and drop it for free with a cost of 4 or less or an enabler
And with its lifelink ability, Griselbrand will regain all those precious life points that you lost