Viridian Corrupter

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Viridian Corrupter enters, destroy target artifact.

Bosk Banneret

Treefolk spells and Shaman spells you cast cost {1} less to cast.

Elvish Visionary

Silverback Shaman

Trample
When this creature dies, draw a card.

Sachi, Daughter of Seshiro

Other Snake creatures you control get +0/+1.
Shamans you control have "{T}: Add {G}{G}."

Centaur Omenreader

As long as this creature is tapped, creature spells you cast cost {2} less to cast.