Goatnap

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. If that creature is a Goat, it also gets +3/+0 until end of turn.

Cleaving Sliver

Mountain

Impostor of the Sixth Pride

Changeling (This card is every creature type.)

Spiteful Sliver

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

Reckless Charge

Target creature gets +3/+0 and gains haste until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Plains

Enduring Sliver

Outlast {2} ({2}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Other Sliver creatures you control have outlast {2}.

Snow-Covered Mountain

First Sliver's Chosen

Sliver creatures you control have exalted. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Serra the Benevolent

+2: Creatures you control with flying get +1/+1 until end of turn.
−3: Create a 4/4 white Angel creature token with flying and vigilance.
−6: You get an emblem with "If you control a creature, damage that would reduce your life total to less than 1 reduces it to 1 instead."

Universal Automaton

Lancer Sliver

Sliver creatures you control have first strike.

Bladeback Sliver

Hellbent — As long as you have no cards in hand, Sliver creatures you control have "{T}: This creature deals 1 damage to target player or planeswalker."

Irregular Cohort

Changeling (This card is every creature type.)
When this creature enters, create a 2/2 colorless Shapeshifter creature token with changeling.

Lavabelly Sliver

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