It has synergies with so so many mechanisms and other cards that combined with its near non-existent cost means it is scaling up in value more than almost any other card in the game
Abilities that trigger whenever a creature enters the battlefield don't trigger
No, as long as you utter a sound that a reasonable person would interpret as a growl
Legality depends on the tournament format -- Herald of Serra can be legal in some formats and banned or restricted in others
Abyssal Gorestalker Abyssal Harvester Abzan Devotee Aclazotz, Deepest Betrayal Acolyte of Aclazotz Adorned Crocodile Adventurous Eater Agate-Blade Assassin Agency Coroner Agent Venom Agents of HYDRA Aggressive Negotiations Aggressive Symbiosis Ahriman Al Bhed Salvagers Alchemist's Assistant Alesha's Legacy Alien Symbiosis Alley Assailant Alpharael, Stonechosen Ambush Gigapede Anchovy & Banana Pizza Ancient Vendetta Another Chance Appendage Amalgam Arbiter of Woe Arcane Omens Archenemy's Charm Ardyn, the Usurper Armaggon, Future Shark Arnim Zola, Bio-Fanatic Arnyn, Deathbloom Botanist Ashiok's Reaper Ashiok, Wicked Manipulator Auntie's Sentence Avenger of the Fallen Azula Always Lies Azula, On the Hunt Back for Seconds Back on Track Bake into a Pie Balemurk Leech Bandit's Talent Bane-Marked Leonin Barbed Bloodletter Barbed Servitor Baron Helmut Zemo Baron Strucker, HYDRA Overlord Barrow Naughty Basilica Stalker Beamsaw Prospector Bebop, Warthog Warrior Beetle-Headed Merchants Behold the Sinister Six
Good boys and girls, all of them
