Collector's Cage is a mythic Artifact card from The Big Score (BIG), collector number 31. Current market price: $5.37 (foil $9.30), TCGplayer market prices via Scryfall.
Hideaway 5 (When this artifact enters, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.) {1}, {T}: Put a +1/+1 counter on target creature you control. Then if you control three or more creatures with different powers, you may play the exiled card without paying its mana cost.