One, the ask of getting a creature card in your graveyard was not a particularly high one
Gallery and List of Freerunning Cards Achilles Davenport Brotherhood Ambushers Chain Assassination Distract the Guards Eagle Vision Escape Detection Ezio Auditore da Firenze Merciless Harlequin Monastery Raid Overpowering Attack Petty Larceny Restart Sequence Viewpoint Synchronization Best Freerunning Cards #5
While the act of milling, putting cards from a player's library directly into their graveyard, can be used against an opponent as a win condition, the act of milling one's self can be quite advantageous if a deck is built around it
According to Scryfall data, there are currently 99 cards with the mutant subtype and 41 that are black and/or green
Abuelos Awakening Abuelo's Awakening was an important part of Omniscience decks before being banned in Standard, allowing you to cheat the 10-mana enchantment into play by paying just 4
You can swarm down your opponents with an armada of fliers or pick them apart over a long game with card drawing from the likes of Mulldrifter and Careful Consideration