Cards that grant evasion make sure it connect, like Whispersilk Cloak or Rogue's Passage, while its built-in recursion ensures it comes back even after dying
Like most Magic: The Gathering cards, the value of The Tarrasque 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 (Adventures in the Forgotten Realms Promos)
Wildcards (used to craft cards) can be found in packs or earned after opening any six packs
If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card
It isn't trying to tell a specific story from a specific timeframe with the set, and it's more of a general environment and setting than anything else