Have

Counterspell

Muscle Sliver

Battering Sliver

Snap

Return target creature to its owner's hand. Untap up to two lands.

Quick Sliver

Flash
Any player may cast Sliver spells as though they had flash.

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Forest

Mutagenic Growth

({G/P} can be paid with either {G} or 2 life.)
Target creature gets +2/+2 until end of turn.

Masked Vandal

Changeling (This card is every creature type.)
When this creature enters, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Getting

Predatory Sliver

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.)

Shadow Sliver

All Sliver creatures have shadow. (They can block or be blocked by only creatures with shadow.)

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.)

Winged Sliver

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Island

Synchronous Sliver

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Bonesplitter Sliver

Two-Headed Sliver

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