Hatchery Sliver + Crookshank Kobolds + Leyline of Transformation

Hatchery Sliver

Crookshank Kobolds

Leyline of Transformation

How it works

1. Cast Crookshank Kobolds by paying 0, and choosing to pay its replicate cost an arbitrarily large number of times by paying 0.
2. Crookshank Kobolds triggers, creating a copy of it for each time its replicate cost was paid.
3. Resolve all Crookshank Kobolds spells, causing the nontoken Crookshank Kobolds to enter the battlefield, and creating a token copy of it for each time its replicate cost was paid.