Siren's Call [Beta Edition] Dragon Set: Legends Type: Creature —

Set: Legends Type: Creature — Demon Rarity: Rare Cost: {3}{B}{B} At end of combat

which can be quite unsettling for their prey

Enchanted Wall can attack as though it didn't have defender

Set: San Diego Comic-Con 2015 Type: Legendary Creature — Elf Scout Rarity: Mythic Cost: {2}{G} When Nissa

if you control twenty or more creatures

Siren's Call [Beta Edition] Dragon Set: Legends Type: Creature —Set: Beta Edition Type: Instant Rarity: Uncommon Cost: {U} Cast this spell only during an opponent's turn, before attackers are declared. Creatures the active player controls attack this turn if able. At the beginning of the next end step, destroy all non Wall creatures that player controls that didn't attack this turn. Ignore this effect for each creature the player didn't control continuously since the beginning of the turn.