Tectonic Giant is a rare Creature — Elemental Giant card from Theros Beyond Death Promos (PTHB), collector number 158p. Current market price: $0.32 (foil $1.27), TCGplayer market prices via Scryfall.
Whenever this creature attacks or becomes the target of a spell an opponent controls, choose one — • This creature deals 3 damage to each opponent. • Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.