Mortuary + Liliana, Dreadhorde General + Cryptic Trilobite

Mortuary

Liliana, Dreadhorde General

Cryptic Trilobite

How it works

1. Cast Cryptic Trilobite by paying 0.
2. Cryptic Trilobite enters and dies as a state-based action due to having 0 toughness, triggering Mortuary and Liliana, Dreadhorde General.
3. Resolve the Mortuary trigger, putting Cryptic Trilobite from your graveyard onto the top of your library.
4. Resolve the Liliana, Dreadhorde General trigger, causing you to draw a card, thus drawing Cryptic Trilobite from your library.
5. Repeat.

This loop relies on the grim synergy between Mortuary and Liliana, Dreadhorde General to turn a persistent tragedy into a fountain of cards. By casting Cryptic Trilobite for zero mana, you immediately send it to the graveyard as a state-based action, which simultaneously satisfies Mortuary's demand to place the creature on top of your library and Liliana, Dreadhorde General's desire to draw a card when a creature you control dies. You simply draw the exact same Cryptic Trilobite you just lost, ready to cast it again for free to generate infinite death triggers, enter-the-battlefield effects, and draw triggers.