Sedge Sliver is a rare Creature — Sliver card from The List (PLST), collector number TSP-177. Current market price: $2.65, TCGplayer market prices via Scryfall.
All Sliver creatures have "This creature gets +1/+1 as long as you control a Swamp." All Slivers have "{B}: Regenerate this permanent." (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)