"What wears down my people most, I think, is not the danger, but the endless screeching outside our camp."
—Merrik Aidar, Benalish patrol

Screeching Sliver

All Slivers have "{T}: Target player mills a card."

Secret Lair Drop

Time Spiral

All Slivers have "{T}: Target player puts the top card of his or her library into his or her graveyard."

Abilities that Slivers grant, as well as power/toughness boosts, are cumulative. However, for some abilities, like flying, having more than one instance of the ability doesn’t provide any additional benefit.

If the creature type of a Sliver changes so it’s no longer a Sliver, it will no longer be affected by its own ability. Its ability will continue to affect other Sliver creatures.