Plumecreed Mentor + Combine Chrysalis + Herd Baloth

Plumecreed Mentor

Combine Chrysalis

Herd Baloth

How it works

1. Cast Plumecreed Mentor by paying 1.
2. When Plumecreed Mentor enters the battlefield, it triggers, putting a +1/+1 counter on Herd Baloth.
3. Herd Baloth triggers, creating a 4/4 Beast creature token that has flying due to Combine Chrysalis.
4. When the Beast enters the battlefield, Plumecreed Mentor triggers, putting a +1/+1 counter on Herd Baloth.
5. Repeat from step 3.