Skithiryx, the Blight Dragon

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{B}: Skithiryx gains haste until end of turn.
{B}{B}: Regenerate Skithiryx.

Mountain

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Forest

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Swamp

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Gwenom, Remorseless

Deathtouch, lifelink
Whenever Gwenom attacks, until end of turn, you may look at the top card of your library any time and you may play cards from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Bygone Colossus

Warp {3} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Venom, Lethal Protector

Menace, trample, haste
Whenever Venom attacks, you may sacrifice another creature. If you do, draw X cards, then you may put a permanent card with mana value X or less from your hand onto the battlefield, where X is the sacrificed creature's mana value.

Eddie Brock

When Eddie Brock enters, return target creature card with mana value 1 or less from your graveyard to the battlefield.
{3}{B}{R}{G}: Transform Eddie Brock. Activate only as a sorcery.

Eddie Brock // Venom, Lethal Protector

Diamond Weapon

This spell costs {1} less to cast for each permanent card in your graveyard.
Reach
Immune — Prevent all combat damage that would be dealt to Diamond Weapon.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Anticausal Vestige

When this creature leaves the battlefield, draw a card, then you may put a permanent card with mana value less than or equal to the number of lands you control from your hand onto the battlefield tapped.
Warp {4} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Sol Ring

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Protean Hulk

When this creature dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

Command Tower

Riveteers Ascendancy

Whenever you sacrifice a creature, you may return target creature card with lesser mana value from your graveyard to the battlefield tapped. Do this only once each turn.

Thought Vessel

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Agent Venom

Flash
Menace
Whenever another nontoken creature you control dies, you draw a card and lose 1 life.

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter with your choice of a +1/+1 counter or haste.)

Anger

Haste
As long as this card is in your graveyard and you control a Mountain, creatures you control have haste.