Big Druid was formulated late in the One Night in Karazhan meta due to the release of the card Barnes and its ability to pull out Y’Shaarj, Rage Unbound from the deck. This could potentially lead to a second Y’Shaarj, or one of the other monstrous minions that occupies a spot in the list.
Now that both Barnes and Y’Shaarj have been pulled out of our Standard decks and into the Wild, this archetype cooled down quite a bit. However, the introduction of Dragonhatcher gave it some life again in the Standard format.
The Boomsday Project didn’t give it a whole lot of new stuff, but Biology Project is a powerful new ramp card that allows this deck type to get to its power turns even quicker.