Hatchery Sliver, Phyrexian Walker, and Arcane Adaptation

Prerequisites

• Hatchery Sliver on the battlefield
• Phyrexian Walker on the battlefield
• Arcane Adaptation on the battlefield
• Arcane Adaptation on the battlefield with "Sliver" chosen

Steps

1. Cast Phyrexian Walker by paying , and choosing to pay its replicate cost an arbitrarily large number of times by paying
2. Phyrexian Walker triggers, creating a copy of it for each time its replicate cost was paid
3. Resolve all Phyrexian Walker spells, causing the nontoken Phyrexian Walker to enter the battlefield, and creating a token copy of it for each time its replicate cost was paid

Results

• Infinite ETB
• Infinite creature tokens