Rock Hydra enters with X +1/+1 counters on it.
For each 1 damage that would be dealt to Rock Hydra, if it has a +1/+1 counter on it, remove a +1/+1 counter from it and prevent that 1 damage. : Prevent the next 1 damage that would be dealt to Rock Hydra this turn. : Put a +1/+1 counter on Rock Hydra. Activate only during your upkeep.
30A · EN 14a1de4b-1237-4e7b-8868-b71e87c9a46e2022-11-28
If damage that would be dealt to Rock Hydra can't be prevented, you still remove a +1/+1 counter from it for each 1 damage dealt.
01-08-2008
wotc
You can activate the activated ability that prevents damage any time, even if no source seems likely to deal damage to you in the near future. It will prevent the next 1 damage that would be dealt this turn, even if that turns out to be much later in the turn.
04-10-2004
wotc
If put onto the battlefield without casting it from your hand, X will be zero.
04-10-2004
wotc
Once on the battlefield, the X is considered to be zero when calculating its mana cost.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.