Tinybones, Bauble Burglar is a rare Legendary Creature — Skeleton Rogue card from Foundations Promos (PFDN), collector number 72s. Current market price: — (foil $4.73), TCGplayer market prices via Scryfall.
Whenever an opponent discards a card, exile it from their graveyard with a stash counter on it. During your turn, you may play cards you don't own with stash counters on them from exile, and mana of any type can be spent to cast those spells. {3}{B}, {T}: Each opponent discards a card. Activate only as a sorcery.