Rock Hydra [Revised Edition] Seventh Edition Counters remain on Skullbriar as

Counters remain on Skullbriar as it moves to any zone other than a player's hand or library

except it's an artifact in addition to its other types

After this phase

Set: Kaladesh Inventions Type: Artifact Mythic Cost: {3} Whenever you activate an ability

Set: Limited Edition Beta Type: Enchantment Rare Cost: {1}{W} If you would draw a card during your draw step

Rock Hydra [Revised Edition] Seventh Edition Counters remain on Skullbriar asSet: Revised Edition Type: Creature Hydra Rare Cost: {X}{R}{R} Rock Hydra enters the battlefield 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. {R}: Prevent the next 1 damage that would be dealt to Rock Hydra this turn. {R}{R}{R}: Put a +1 +1 counter on Rock Hydra. Activate this ability only during your upkeep.