Rock Hydra [Beta Edition] Rivals of Ixalan Prerelease Promos "Tell me again

"Tell me again

Athenian Teacher has hexproof as long as it's untapped

final research note

if Nether Shadow is in your graveyard with three or more creature cards above it

When it attacks

Rock Hydra [Beta Edition] Rivals of Ixalan Prerelease Promos "Tell me againSet: Beta Edition Type: Creature Hydra Rarity: 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 only during your upkeep.