Multicolor Eloise triggers on Clue tokens, Treasures, and when you inevitably sacrifice the creatures you create with Endrek Sahr, Master Breeder
Creatures like Piper of the Swarm, Totentanz, Swarm Piper, and Ogre Slumlord can ensure your field is consistently full of rats, and the nonlegendary Piper even lets you use them to steal your opponents creatures
Timing restrictions based on the cards type are ignored
If you need something to store cards for decks you plan to build or playsets you like to have on hand, you might be more inclined to search for an Ultra-Pro 4-pocket Pro binder
So keep an eye on this space for when more reveals are announced
He doesn't copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on