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.

Toxin Sliver

Whenever a Sliver deals combat damage to a creature, destroy that creature. It can't be regenerated.

Sinew Sliver

Sliver Gravemother

The "legend rule" doesn't apply to Slivers you control.
Each Sliver creature card in your graveyard has encore {X}, where X is its mana value.
Encore {5} ({5}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Leeching Sliver

Whenever a Sliver you control attacks, defending player loses 1 life.

Sliver Overlord

{3}: Search your library for a Sliver card, reveal that card, put it into your hand, then shuffle.
{3}: Gain control of target Sliver. (This effect lasts indefinitely.)

Sidewinder Sliver

All Sliver creatures have flanking. (Whenever a creature without flanking blocks a Sliver, the blocking creature gets -1/-1 until end of turn.)

Clot Sliver

All Slivers have "{2}: Regenerate this permanent."

Sliver Hivelord

Sliver creatures you control have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Heart Sliver

Hive Stirrings

Create two 1/1 colorless Sliver creature tokens.

Psionic Sliver

All Sliver creatures have "{T}: This creature deals 2 damage to any target and 3 damage to itself."

Taunting Sliver

Sliver creatures you control have "When this creature enters, goad target creature an opponent controls." (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Constricting Sliver

Sliver creatures you control have "When this creature enters, you may exile target creature an opponent controls until this creature leaves the battlefield."

Mistform Sliver

All Slivers have "{1}: This permanent becomes the creature type of your choice in addition to its other types until end of turn."