Hatchery Sliver + Kobolds of Kher Keep + Leyline of Transformation

Hatchery Sliver

Kobolds of Kher Keep

Leyline of Transformation

How it works

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