Berta, Wise Extrapolator + Ghave, Guru of Spores + Ashnod's Altar + Pir, Imaginative Rascal

Berta, Wise Extrapolator

Ghave, Guru of Spores

Ashnod's Altar

Pir, Imaginative Rascal

How it works

1. Activate Ghave's first ability by paying 1 and removing a +1/+1 counter from a creature you control, creating a 1/1 Saproling creature token.
2. Activate Ashnod's Altar by sacrificing the Saproling, adding CC.
3. Activate Ghave's first ability by paying 1 and removing a +1/+1 counter from a creature you control, creating a 1/1 Saproling creature token.
4. Activate Ghave's second ability by paying 1 and sacrificing the Saproling, putting two +1/+1 counters on Berta due to Pir.
5. Berta triggers, adding 1.
6. Repeat.