Arbor Elf + Pemmin's Aura + Breeding Pool + Utopia Sprawl

Arbor Elf
Pemmin's Aura
Breeding Pool
Utopia Sprawl

Requires
All permanents on the battlefield. Arbor Elf does not have summoning sickness. Pemmin's Aura attached to Arbor Elf. Utopia Sprawl attached to Breeding Pool. "Blue" chosen with Utopia Sprawl.
Steps
  1. Activate Breeding Pool by tapping it, adding ug
  2. Activate Arbor Elf by tapping it, untapping Breeding Pool
  3. Activate Pemmin's Aura's first ability by paying u, untapping Arbor Elf
  4. Repeat
Results
Infinite green mana. Infinite blue mana.