4 Oct 2004
If the Oyster untaps during the draw step before its ability to add a -1/-1 counter resolves, the -1/-1 counter effect resolves and adds a -1/-1 counter after the -1/-1 counters are removed due to being untapped.
25 Sept 2006
Activating the ability creates a continuous effect that works only as long as Giant Oyster remains tapped, a repeating delayed triggered ability that’s in effect only as long as Giant Oyster remains tapped, and a delayed triggered ability that triggers when Giant Oyster untaps or when it leaves the battlefield.
25 Sept 2006
Giant Oyster’s ability can be activated during your upkeep, and the creature will get a -1/-1 counter during the draw step that follows it.
25 Sept 2006
The activated ability can target only a tapped creature.