Make Basal Thrulls

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead. If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

All Slivers have "Sacrifice this permanent: Add ."

As this enchantment enters, choose a creature type. Creatures you control are the chosen type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

At the beginning of your upkeep, sacrifice this enchantment unless you pay . At the beginning of your end step, create a 0/1 black Thrull creature token.