Unsettled Mariner

Changeling (This card is every creature type.)
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

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.)

Shapesharer

Changeling (This card is every creature type.)
{2}{U}: Target Shapeshifter becomes a copy of target creature until your next turn.

Harmonic Sliver

All Slivers have "When this permanent enters the battlefield, destroy target artifact or enchantment."

Syphon Sliver

Sliver creatures you control have lifelink. (Damage dealt by a Sliver creature you control also causes you to gain that much life.)

Sinew Sliver

Victual Sliver

All Slivers have "{2}, Sacrifice this permanent: You gain 4 life."

Frenzy Sliver

All Sliver creatures have frenzy 1. (Whenever a Sliver attacks and isn't blocked, it gets +1/+0 until end of turn.)

Blade Sliver

Frenetic Sliver

All Slivers have "{0}: If this permanent is on the battlefield, flip a coin. If you win the flip, exile this permanent and return it to the battlefield under its owner's control at the beginning of the next end step. If you lose the flip, sacrifice it."

Steelform Sliver

Dregscape Sliver

Each Sliver creature card in your graveyard has unearth {2}.
Unearth {2} ({2}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Gemhide Sliver

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

Sentinel Sliver

Sliver creatures you control have vigilance. (Attacking doesn't cause them to tap.)

Plated Sliver

Lancer Sliver

Sliver creatures you control have first strike.

Spiteful Sliver

Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."

Crystalline Sliver

All Slivers have shroud. (They can't be the targets of spells or abilities.)

Predatory Sliver

Shadow Sliver

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

Galerider Sliver

Sliver creatures you control have flying.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters the battlefield, choose a creature type.
Whenever another creature of the chosen type enters the battlefield under your control, put a +1/+1 counter on Bloodline Pretender.

Hatchery Sliver

Replicate {1}{G} (When you cast this spell, copy it for each time you paid its replicate cost.)
Each Sliver spell you cast has replicate. The replicate cost is equal to its mana cost. (A copy of a permanent spell becomes a token.)

Two-Headed Sliver

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

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.)

Venom Sliver

Sliver creatures you control have deathtouch. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.)

Crypt Sliver

All Slivers have "{T}: Regenerate target Sliver."

Darkheart Sliver

All Slivers have "Sacrifice this permanent: You gain 3 life."

Spined Sliver

Whenever a Sliver becomes blocked, that Sliver gets +1/+1 until end of turn for each creature blocking it.

Winged Sliver

Firewake Sliver

All Sliver creatures have haste.
All Slivers have "{1}, Sacrifice this permanent: Target Sliver creature gets +2/+2 until end of turn."

Cloudshredder Sliver

Sliver creatures you control have flying and haste.

Sedge Sliver

All Sliver creatures have "This creature gets +1/+1 as long as you control a Swamp."
All Slivers have "{B}: Regenerate this permanent." (The next time it would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

Diffusion Sliver

Whenever a Sliver creature you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.

Muscle Sliver

Spinneret Sliver

Heart Sliver

Quick Sliver

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

Leeching Sliver

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

Talon Sliver

Belligerent Sliver

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

Striking Sliver

Sliver creatures you control have first strike. (They deal combat damage before creatures without first strike.)

Opaline Sliver

All Slivers have "Whenever this permanent becomes the target of a spell an opponent controls, you may draw a card."

Lavabelly Sliver

Sliver creatures you control have "When this creature enters the battlefield, it deals 1 damage to target player or planeswalker and you gain 1 life."

Manaweft Sliver

Sliver creatures you control have "{T}: Add one mana of any color."

Mnemonic Sliver

All Slivers have "{2}, Sacrifice this permanent: Draw a card."

Najeela, the Blade-Blossom

Whenever a Warrior attacks, you may have its controller create a 1/1 white Warrior creature token that's tapped and attacking.
{W}{U}{B}{R}{G}: Untap all attacking creatures. They gain trample, lifelink, and haste until end of turn. After this phase, there is an additional combat phase. Activate only during combat.

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.)

Tempered Sliver

Sliver creatures you control have "Whenever this creature deals combat damage to a player, put a +1/+1 counter on it."

Quilled Sliver

All Slivers have "{T}: This permanent deals 1 damage to target attacking or blocking creature."