Filling your graveyard with Surveil on top of regular spellcasting, it's easy to quickly load your graveyard to unleash a devastating amount of damage while whittling away your opponents' creatures
Like most Magic: The Gathering cards, the value of Metallic Mimic depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (The Lost Caverns of Ixalan Commander)
Additionally, there is another layer of black afterwards for the text, mana symbols, and borders
These are technically Magic fronted Wyvern cards since they were only found in Wyvern starters
My first run in with it was an Umezawa's Jitte by Gus Schade, aka yawg07, on MTGSalvation
In terms of popularity, the Borderless Surge Foil is shoulders above the rest, but the Normal print is also exceedingly popular right now according to TCGPlayer, and still one of the top 20 cards players have been chasing since the new set released