Also, we skip the cards with two names like modal-double face cards, transforming cards, and split cards like Aang, at the Crossroads/Aang, Destined Savior are not in contention
While the card has not seen much play outside the aptly named Blue-Red Murktide deck, the archetype has been one of the best decks in Modern since Modern Horizons 2 and continues to be so, and it is all thanks to this card
One Piece
No activated abilities of the target nonland permanent can be activated for as long as it remains tapped, even if those activated abilities' costs involve untapping that permanent
Avenger of ZendikarAvenger of Zendikar and Phylath, World SculptorPhylath, World Sculptor: While not Plants themselves, they create a large amount of Plants, which is perfect for combos with Nim DeathmantleNim Deathmantle and Mana EchoesMana Echoes
There are a lot of useful Rats you want to stick on the battlefield, and Swarmyard helps make your opponents require two removal spells if they ever want to take care of a Rat