All Sliver creatures have "This creature gets +1/+1 as long as you control a Swamp."
All Slivers have ": 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.)
: 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.)