Basalt Monolith + Tough Cookie + Training Grounds

Basalt Monolith

Tough Cookie

Training Grounds

How it works

1. Activate Basalt Monolith's first ability by tapping it, adding CCC.
2. Activate Tough Cookie's first activated ability by paying 2, making Basalt Monolith a 4/4 artifact creature until end of turn.
3. Activate Basalt Monolith's last ability by paying 1, untapping it.
4. Activate Basalt Monolith's first ability by tapping it, adding CCC.
5. Repeat from step 3.

By turning our mana rock into an animated creature, this combo cleverly unlocks an infinite loop. While Basalt Monolith normally costs three mana to untap, the discount provided by Training Grounds reduces that cost down to just one mana. Because tapping the Monolith yields three colorless mana and untapping it only costs one, you generate a net profit of two colorless mana on every single cycle. Meanwhile, the initial Food token created when Tough Cookie enters the battlefield is just a nice bonus left over while you use the Cookie's animation ability to keep the engine running.