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.)

Pulmonic Sliver

All Sliver creatures have flying.
All Slivers have "If this permanent would be put into a graveyard, you may put it on top of its owner's library instead."

Kher Keep

{T}: Add {C}.
{1}{R}, {T}: Create a 0/1 red Kobold creature token named Kobolds of Kher Keep.

Battering Sliver

Dryad Arbor

(This land isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Fungal Reaches

{T}: Add {C}.
{1}, {T}: Put a storage counter on this land.
{1}, Remove X storage counters from this land: Add X mana in any combination of {R} and/or {G}.

Spinneret Sliver

Lymph Sliver

All Sliver creatures have absorb 1. (If a source would deal damage to a Sliver, prevent 1 of that damage.)

Shivan Meteor

Shivan Meteor deals 13 damage to target creature.
Suspend 2—{1}{R}{R} (Rather than cast this card from your hand, you may pay {1}{R}{R} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Two-Headed Sliver

All Sliver creatures have menace. (They can't be blocked except by two or more creatures.)

Mana Tithe

Counter target spell unless its controller pays {1}.

Sinew Sliver

Bound in Silence

Enchant creature
Enchanted creature can't attack or block.

Watcher Sliver

Mountain

Reflex Sliver

Forest

Gone

Return target creature you don't control to its owner's hand.

Dead

Dead // Gone

Plains

Virulent Sliver

All Sliver creatures have poisonous 1. (Whenever a Sliver deals combat damage to a player, that player gets a poison counter. A player with ten or more poison counters loses the game.)

Strength in Numbers

Until end of turn, target creature gains trample and gets +X/+X, where X is the number of attacking creatures.

Sunlance

Sunlance deals 3 damage to target nonwhite creature.

Fury Sliver

Poultice Sliver

All Slivers have "{2}, {T}: Regenerate target Sliver." (The next time that Sliver would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Homing Sliver

Each Sliver card in each player's hand has slivercycling {3}.
Slivercycling {3} ({3}, Discard this card: Search your library for a Sliver card, reveal it, put it into your hand, then shuffle.)