Have

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Oliphaunt

Trample
Whenever Oliphaunt attacks, another target creature you control gets +2/+0 and gains trample until end of turn.
Mountaincycling {1} ({1}, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

Cast Down

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Swamp

Echoing Ruin

Destroy target artifact and all other artifacts with the same name as that artifact.

Dragon Breath

Enchant creature
Enchanted creature has haste.
{R}: Enchanted creature gets +1/+0 until end of turn.
When a creature with mana value 6 or greater enters, you may return Dragon Breath from your graveyard to the battlefield attached to that creature.

Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents.)
Ulamog's Crusher attacks each combat if able.

Exhume

Each player puts a creature card from their graveyard onto the battlefield.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mountain

Krark-Clan Shaman

Sacrifice an artifact: Krark-Clan Shaman deals 1 damage to each creature without flying.

Rust Goliath

Prototype {3}{G}{G} — 3/5 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Reach, trample

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Riveteers Overlook

When Riveteers Overlook enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Toxin Analysis

Target creature gains deathtouch and lifelink until end of turn. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Geothermal Bog

({T}: Add {B} or {R}.)
Geothermal Bog enters tapped.

Voldaren Epicure

When Voldaren Epicure enters, it deals 1 damage to each opponent. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")