The ability to turn into any kind of animal has to be somewhat useful
However, if you can find a way to discard Emrakul for cheap, you can reduce Emrakuls casting cost significantly
To assist you with that, the deck includes combat finishers like Return of the WildspeakerReturn of the Wildspeaker and Akromas WillAkromas Will
Thanks to this, you can play all the best creatures and spells with Proliferate, alongside classic Infect cards
For example, an X mana symbol does not usually add anything to a cards mana value, except in specific situations
Think about the creatures you can afford to reanimate (or hard cast) when designing your deck (and mana base), and also the additional utility of cards like Eureka, and how they could potentially interact with large creatures stuck in hand