Trenzalore Clocktower is a rare Legendary Land card from Doctor Who (WHO), collector number 463. Current market price: $1.02 (foil $1.51), TCGplayer market prices via Scryfall.
{T}: Add {U}. Put a time counter on Trenzalore Clocktower. {1}{U}, {T}, Remove twelve time counters from Trenzalore Clocktower and exile it: Shuffle your graveyard and hand into your library, then draw seven cards. Activate only if you control a Time Lord.