Assume withunless otherwise mentioned

Alhammarret's Archive – What if we could draw thirty instead of fifteen. Also, cycling lands like Barren Moor become insane with Girtrog and the archive in play. It’s better than Ancestral Recall .

Amulet of Vigor + Scapeshift or Splendid Reclamation – Sure, I will basically not spend mana to refill my mana pool. Also an interesting interaction with Mesmeric Orb .

Crucible of Worlds – I think this is self-evident. We are sacrificing our lands a lot. Let’s make that an easier pill to swallow.

Dakmor Salvage – A land with dredge, in a deck that cares about lands hitting the yard. Seems good. This is probably the most important land in the deck. My game plan gets a lot harder when I lose it to exile.

Mesmeric Orb – This is how you draw fifteen cards before your draw step. Because each mill is individual, it does take awhile to resolve, but it is extremely powerful to mill several lands and then draw for each.

Squandered Resources – If you look at the TCGPlayer page for this card, you can pinpoint the exact time The Gitrog Monster was spoiled, based only on the price history graph. It is truly insane in this deck.