Mortuary + Garruk's Horde + Stonecoil Serpent

Mortuary

Garruk's Horde

Stonecoil Serpent

How it works

1. Cast Stonecoil Serpent either from your hand or from the top of your library by paying 0.
2. Stonecoil Serpent enters the battlefield and dies as a state-based action due to having zero toughness.
3. Mortuary triggers, putting Stonecoil Serpent on top of your library from your graveyard.
4. Repeat.

This clever loop turns the zero-cost casting of Stonecoil Serpent into an endless mechanical engine right off the top of your library. As the Serpent repeatedly enters the battlefield and instantly hits the graveyard with zero toughness, Mortuary catches it every single time and dutifully stacks it right back on top of your library. Meanwhile, Garruk's Horde lets you play right through that top-deck restriction, turning this zero-mana cycle into infinite creature enters-the-battlefield triggers, death triggers, and a massive storm count.