Thrumming Hivepool is a rare Artifact card from Edge of Eternities Promos (PEOE), collector number 247p. Current market price: $1.04 (foil $1.53), TCGplayer market prices via Scryfall.
Affinity for Slivers (This spell costs {1} less to cast for each Sliver you control.) Slivers you control have double strike and haste. At the beginning of your upkeep, create two 1/1 colorless Sliver creature tokens.