Most played cards in Zoo:

4 Decks
Lightning Bolt
15 copies - 3.75 average
Terramorphic Expanse
14 copies - 3.5 average
Rancor
12 copies - 3 average
Pyroblast
12 copies - 3 average
Wild Nacatl
12 copies - 3 average
Kird Ape
10 copies - 2.5 average
Squadron Hawk
8 copies - 2 average
Electrickery
8 copies - 2 average
Tribal Flames
8 copies - 2 average
Nylea's Presence
8 copies - 2 average
Matca Rioters
7 copies - 1.75 average
Gorilla Shaman
7 copies - 1.75 average
Evolving Wilds
7 copies - 1.75 average
Abundant Growth
7 copies - 1.75 average
Kor Skyfisher
6 copies - 1.5 average
Unearth
5 copies - 1.25 average
Young Wolf
5 copies - 1.25 average
Basking Rootwalla
4 copies - 1 average
Faithless Looting
4 copies - 1 average
Wild Mongrel
4 copies - 1 average