Bomat Courier

Haste
Whenever this creature attacks, exile the top card of your library face down. (You can't look at it.)
{R}, Discard your hand, Sacrifice this creature: Put all cards exiled with this creature into their owners' hands.

Oliphaunt

Trample
Whenever this creature 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.)

Dwarven Mine

({T}: Add {R}.)
This land enters tapped unless you control three or more other Mountains.
When this land enters untapped, create a 1/1 red Dwarf creature token.

Mountain

Subira, Tulzidi Caravanner

Haste
{1}: Another target creature with power 2 or less can't be blocked this turn.
{1}{R}, {T}, Discard your hand: Until end of turn, whenever a creature you control with power 2 or less deals combat damage to a player, draw a card.

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Mishra, Excavation Prodigy

Haste
{1}, {T}, Discard a card: Draw a card.
Whenever you discard one or more artifact cards, add {R}{R}. This ability triggers only once each turn.

Clockwork Servant

Adamant — When this creature enters, if at least three mana of the same color was spent to cast it, draw a card.

Mad Ratter

Whenever you draw your second card each turn, create two 1/1 black Rat creature tokens.

Galvanic Discharge

Choose target creature or planeswalker. You get {E}{E}{E} (three energy counters), then you may pay any amount of {E}. Galvanic Discharge deals that much damage to that permanent.

Forgotten Cave

This land enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Scorching Shot

Scorching Shot deals 5 damage to target creature.

Scrapwork Mutt

When this creature enters, you may discard a card. If you do, draw a card.
Unearth {1}{R} ({1}{R}: 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.)

Zookeeper Mechan

{T}: Add {R}.
{6}{R}: Target creature you control gets +4/+0 until end of turn. Activate only as a sorcery.

Mishra's Research Desk

{1}, {T}, Sacrifice this artifact: Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.
Unearth {1}{R} ({1}{R}: Return this card from your graveyard to the battlefield. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)