Pentavus + Dross Scorpion + Stonespeaker Crystal

Pentavus

Dross Scorpion

Stonespeaker Crystal

How it works

1. Activate Stonespeaker Crystal by tapping it, adding CC.
2. Activate Pentavus's first ability by paying 1 and removing a +1/+1 counter from it, creating a 1/1 Pentavite creature token.
3. Activate Pentavus's second ability by paying 1 and sacrificing the Pentavite.
4. When the Pentavite dies, Dross Scorpion triggers, untapping Stonespeaker Crystal.
5. Resolve the Pentavus ability, putting a +1/+1 counter on it.
6. Repeat.