Ambush Viper

Coiled Tinviper

Blight Mamba

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{1}{G}: Regenerate Blight Mamba.

Ankle Biter

Coiling Stalker

Ninjutsu {1}{G} ({1}{G}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Coiling Stalker deals combat damage to a player, put a +1/+1 counter on target creature you control that doesn't have a +1/+1 counter on it.

Bamboo Grove Archer

Defender, reach
Channel — {4}{G}, Discard Bamboo Grove Archer: Destroy target creature with flying.

Anaconda

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)