You want cards that work as mass artifact destruction as cheaply as possible, so Farewell usually wont do it at 6 mana
Ancient Hydra Apex Devastator Apocalypse Hydra Balduvian Hydra Benevolent Hydra Bioessence Hydra Briar Hydra Bristling Hydra Capricopian Clockwork Hydra Domesticated Hydra Feral Hydra Gargos, Vicious Watcher Genesis Hydra Goldvein Hydra Grakmaw, Skyclave Ravager Gyrus, Waker of Corpses Heroes' Bane Honored Hydra Hooded Hydra Hungering Hydra Hydra Broodmaster Hydra Omnivore Hydradoodle Hydroid Krasis Ironscale Hydra Kalonian Hydra Khalni Hydra Lifeblood Hydra Managorger Hydra Mistcutter Hydra Molten Hydra Mossborn Hydra Multi-Headed Nessian Wilds Ravager Neverwinter Hydra Nyxborn Hydra Oran-Rief Hydra Phyrexian Hydra Phytohydra Polukranos Reborn Polukranos, Engine of Ruin Polukranos, Unchained Polukranos, World Eater Primordial Hydra Progenitus Protean Hydra Rampaging Aetherhood Rampant Rejuvenator Ramunap Hydra Rock Hydra Savageborn Hydra Scourge of Skola Vale Shivan Devastator Spitting Hydra Sprouting Phytohydra Steelbane Hydra Steelbane Hydra Stumpsquall Hydra The Goose Mother Thunderous Snapper Ulasht, the Hate Seed Ulvenwald Hydra Vastwood Hydra Voracious Hydra Voracious Hydra Warden of the Grove Whiptongue Hydra Wildwood Scourge Wren's Run Hydra Zaxara, the Exemplary
Like Dromoka, Wrexial also has a Secret Lair version that takes a lot of artistic liberty with the original artists depiction, as seen here by Alexandre Chaudret from three years ago
Misspellings in names, attacks, or descriptions are another giveaway and should raise suspicion immediately
Giratina ex barely moves at all in its animation
Delirium Unholy Heat deals 6 damage instead if there are four or more card types among cards in your graveyard
