Glistener Seer is a common Creature — Phyrexian Advisor card from Phyrexia: All Will Be One (ONE), collector number 54. Current market price: $0.25 (foil $0.17), TCGplayer market prices via Scryfall.
This creature enters with three oil counters on it. {T}, Remove an oil counter from this creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)