Cast Chain of Smog by paying {1}{B}, targeting yourself.
Karok Wrangler triggers, putting a +1/+1 counter on a creature you control.
Resolve Chain of Smog, causing you to discard two cards and copy Chain of Smog, targeting yourself.
Repeat from step 2.

Infinite +1/+1 counters

Infinite magecraft triggers

Chain of Smog

Karok Wrangler

Cast Chain of Acid by paying {3}{G}, targeting an indestructible noncreature permanent you control.
Karok Wrangler triggers, putting a +1/+1 counter on a creature you control.
Resolve Chain of Acid, destroying nothing and causing you to copy Chain of Acid, targeting an indestructible noncreature permanent you control.
Repeat from step 2.

Combos with "Karok Wrangler"