Slum Stalker
Creature - Cat (U)
Prowl
When ~ enters the battlefield, it gets haste and vigilance until end of turn. If its Prowl cost was paid, it deals damage equal to its power to any target that was dealt damage this turn.
[3/2]

Trail of Breadcrumbs
Instant
Return target land card in your graveyard to your hand.
Retrace

Frostfire Phytohydra —
Creature — Weird Hydra (C)
: Frostfire Phytohydra gains +1/+0 until end of turn.
: Frostfire Phytohydra gains skulk until end of turn.
2/2

Treacherous Merchant
Creature - Human Peasant (C)
Traitor (You may cast this spell for its traitor cost. If you do, it enters the battlefield under an opponent's control, and it’s sacrificed when it enters the battlefield.)
When Treacherous Merchant enters the battlefield, exile the top card of your library. Until end of turn, Treacherous Merchant's owner may play that card and mana of any type can be spent to cast it.
"That trader's a traitor!"
3/2

Spark Hellion
Creature - Devil
Undying
~ has haste, trample, and decayed as long as it has a +1/+1 counter on it.
"All it takes is a single spark to light the night ablaze!"
[2/1]

Rearguard Cavalier

Creature - Human Knight
Flash (You may cast this spell any time you could cast an instant.)
First strike
When Rearguard Cavalier enters, target creature must yield. (When a creature must yield, untap it and remove it from combat. It can't attack or block this turn.)
3/2

Purphoros's Elemental —
Creature — Elemental (U)
Trample
Zoom (You may play this card for its zoom cost. If you do, it gains haste. Sacrifice it at the beginning of the next end step.)
4/1

Garrison Patrol
Creature - Human Soldier
When ~ enters, target creature you control gains indestructible until end of turn.
Blitz
You may cast ~ as though it has flash if you pay its blitz cost.
[2/1]

Backdoor Eavesdropping

Sorcery
Surveil 3 (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Rockslide Elemental —
Creature — Elemental (U)
Trample
Dash (You may cast this spell for its dash cost. If you do, it gains haste, and it’s returned from the battlefield to its owner’s hand at the beginning of the next end step.)
4/1