Ogdoadic Hollow

Whenever you sacrifice a Snake creature, put a hollow counter on Ogdoadic Hollow.

{t}, Remove a hollow counter from Ogdoadic Hollow: Return target Ogdoadic creature card from your exile to your graveyard.

{t}, Remove X hollow counters from Ogdoadic Hollow: Return target Ogdoadic creature with mana value X or less from your graveyard to the battlefield with a finality counter on it.