Night Scythe

Flying
Invasion Beams — When Night Scythe enters, create a 2/2 black Necron Warrior artifact creature token.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Heart of Kiran

Flying, vigilance
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)
You may remove a loyalty counter from a planeswalker you control rather than pay Heart of Kiran's crew cost.

Sky Skiff

Flying
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Rathi Assassin

{1}{B}{B}, {T}: Destroy target tapped nonblack creature.
{3}, {T}: Search your library for a Mercenary permanent card with mana value 3 or less, put it onto the battlefield, then shuffle.

Strongarm Thug

When Strongarm Thug enters, you may return target Mercenary card from your graveyard to your hand.

Thunderhawk Gunship

Flying
When Thunderhawk Gunship enters, create two 2/2 white Astartes Warrior creature tokens with vigilance.
Whenever Thunderhawk Gunship attacks, attacking creatures you control gain flying until end of turn.
Crew 2

Mari, the Killing Quill

Whenever a creature an opponent controls dies, exile it with a hit counter on it.
Assassins, Mercenaries, and Rogues you control have deathtouch and "Whenever this creature deals combat damage to a player, you may remove a hit counter from a card that player owns in exile. If you do, draw a card and create two Treasure tokens."

Skysovereign, Consul Flagship

Flying
Whenever Skysovereign, Consul Flagship enters or attacks, it deals 3 damage to target creature or planeswalker an opponent controls.
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)

Alley Grifters

Whenever Alley Grifters becomes blocked, defending player discards a card.

Silent Assassin

{3}{B}: Destroy target blocking creature at end of combat.

Aethersphere Harvester

Flying
When Aethersphere Harvester enters, you get {E}{E} (two energy counters).
Pay {E}: Aethersphere Harvester gains lifelink until end of turn.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Phyrexian Driver

When Phyrexian Driver enters, other Mercenary creatures get +1/+1 until end of turn.