Requires

Wick, the Whorled Mind must be in hand, or in the command zone. Shilgengar, Sire of Famine must be on the battlefield. Leyline of Transformation must be on the battlefield (with "Rat" chosen). Mana needed: plus enough mana to pay for commander tax, if applicable

Steps

1. Cast Wick either from your hand or from the command zone by paying plus commander tax, if applicable.
2. When Wick enters the battlefield, it triggers.
3. Holding priority, if you control a Snail, activate Shilgengar by sacrificing the Snail, creating a Blood token.
4. If needed, repeat step 3 until you do not control a Snail.
5. Resolve the Wick trigger, creating a 1/1 Snail creature token.
6. When the Snail enters the battlefield as a Rat due to Leyline of Transformation, Wick triggers.
7. Repeat from step 3.

Results