Although the obvious advice would be to buy whatever is available to you, given the set's high demand, certain products are better options than others
At most you may get a few other members of its species in the background (like Astral Radiances Stantler), but having others show up in the same art is done maybe once or twice an expansion at most
In line with this, "waking up" Dragulas is a bad idea, for if it is flipped face-up, its effect sends a card on the field to the Graveyard
White Aura Whale can attack (monsters) up to twice per turn, and when it attacks a defense position monster, youll be inflicting piercing damage too
Even if you don't have the creatures to charge it, its enter trigger lets you search for a legendary creature and put it into your hand