Sedge Sliver is a rare Creature — Sliver card from Time Spiral (TSP), collector number 177. Current market price: $1.17 (foil $20.22), 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.)