Basal Sliver

All Slivers have "Sacrifice this permanent: Add {B}{B}."

Hollowhead Sliver

Sliver creatures you control have "{T}, Discard a card: Draw a card."

The First Sliver

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Sliver spells you cast have cascade.

Living End

Suspend 3—{2}{B}{B}
Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Cloudshredder Sliver

Sliver creatures you control have flying and haste.