Conspiracy + Turntimber Ranger + Concordant Crossroads

Conspiracy

Turntimber Ranger

Concordant Crossroads

How it works

1. Cast Turntimber Ranger by paying 3.
2. Turntimber Ranger enters the battlefield, creating a 2/2 Wolf creature token and putting a +1/+1 counter on Turntimber Ranger.
3. 2/2 Wolf creature token enters the battlefield triggering Turntimber Ranger, creating a 2/2 Wolf creature token and putting a +1/+1 counter on Turntimber Ranger.
4. Repeat from step 2.