Voracious Hydra [Secret Lair Drop Series] 38 and has "Whenever a player

and has "Whenever a player casts a spell or a creature attacks

Set: Unknown Event Type: Creature — Human Rarity: Common Whenever Shahrazad and Sindband deals combat damage to an opponent

Set: Unknown Event Type: Artifact Creature — Goblin Wizard Rarity: Common Cost: {2} T: Exile the top card of your library

up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value

(They deal both first-strike and regular combat damage

Voracious Hydra [Secret Lair Drop Series] 38 and has "Whenever a playerSet: Secret Lair Drop Series Type: Creature Hydra Rarity: Rare Cost: {X}{G}{G} Trample Voracious Hydra enters the battlefield with X +1 +1 counters on it. When Voracious Hydra enters the battlefield, choose one Double the number of +1 +1 counters on Voracious Hydra. Voracious Hydra fights target creature you don't control.