Mirelurk Queen
Earthcraft is currently banned in Legacy
Draft Boosters: Click To Pre-Order Yours From | TCGplayer | eBay | or | Amazon | Each Dominaria Remastered Draft Booster contains 15 cards and 1 token/ad card, including 1 card of rarity Rare or higher and 24 Uncommon, 911 Common, and 1 Retro Land cards
Unlike many higher hitting stuff you don't have to hold out mana or keep something untapped like a dork or a land, you can just do your thing and then keep the Chains ready
(It loses its other colors and creature types.) If a player is instructed to put a card into their graveyard from their library without using the word "mill," (by the effect of Rowan's Grim Search from Wilds of Eldraine , for example), that card isn't a legal target for The Master's last ability
A land destruction spell can destroy it, but not a creature destruction spell