Swamp

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Duress

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

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.)

Mountain

Hordeling Outburst

Create three 1/1 red Goblin creature tokens.

Exhume

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

Dark Ritual

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.

Sulfurous Mire

({T}: Add {B} or {R}.)
Sulfurous Mire enters tapped.

Putrid Imp

Discard a card: Putrid Imp gains flying until end of turn.
Threshold — As long as seven or more cards are in your graveyard, Putrid Imp gets +1/+1 and can't block.

Ulamog's Crusher

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

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

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.)

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.)

Bitter Reunion

When Bitter Reunion enters, you may discard a card. If you do, draw two cards.
{1}, Sacrifice Bitter Reunion: Creatures you control gain haste until end of turn.