Inkmoth Nexus

Oracle Text

T: Add C to your mana pool.

1: Inkmoth Nexus becomes a 1/1 Blinkmoth artifact creature with flying and infect until end of turn. It's still a land. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Card Rulings

6/1/2011 If Inkmoth Nexus entered the battlefield this turn and it's not a creature, it can be tapped for mana. If it becomes a creature that turn, it can't attack or be tapped for mana.
6/1/2011 If you've controlled Inkmoth Nexus continuously since your most recent turn began and it becomes a creature, it can attack or be tapped for mana.