Spinal Post

At the begennong of your endstep if you Control Spinal Post, Harvesting Hands,
Hooded Pumpkin, and Cobbled Casings, shuffle Spinal Post and your graveyard into
your library. After all triggers have been resolved meld Spinal Post, Harvesting Hands, Hooded Pumpkin, and Cobbled Casings into Doomcrow.