Grim Poppet + Quicksilver Gargantuan + Hapatra, Vizier of Poisons

Grim Poppet

Quicksilver Gargantuan

Hapatra, Vizier of Poisons

How it works

1. Activate Grim Poppet by removing a -1/-1 counter from it, putting a -1/-1 counter on Quicksilver Gargantuan.
2. Hapatra triggers, creating a creature token.
3. Activate Quicksilver Gargantuan by removing a -1/-1 counter from it, putting a -1/-1 counter on Grim Poppet.
4. Hapatra triggers, creating a creature token.
5. Repeat.