Most played cards in Zoo:

1 Decks
Arid Mesa
4 copies - 4 average
Destructive Revelry
4 copies - 4 average
Burning-Tree Emissary
4 copies - 4 average
Lightning Bolt
4 copies - 4 average
Wooded Foothills
4 copies - 4 average
Windswept Heath
4 copies - 4 average
Atarka's Command
4 copies - 4 average
Wild Nacatl
4 copies - 4 average
Goblin Guide
4 copies - 4 average
Experiment One
4 copies - 4 average
Hidden Herbalists
4 copies - 4 average
Kird Ape
4 copies - 4 average
Reckless Bushwhacker
4 copies - 4 average
Narnam Renegade
4 copies - 4 average
Rest in Peace
2 copies - 2 average
Grafdigger's Cage
2 copies - 2 average
Deflecting Palm
2 copies - 2 average
Thalia, Guardian of Thraben
2 copies - 2 average
Simian Spirit Guide
2 copies - 2 average
Stomping Ground
2 copies - 2 average