Guardian Sunmare

Ward {2}
Whenever this creature attacks while saddled, search your library for a nonland permanent card with mana value 3 or less, put it onto the battlefield, then shuffle.
Saddle 4

Temple of Plenty

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {G} or {W}.

Gloryheath Lynx

Lifelink
Whenever this creature attacks while saddled, search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Plains

Thunderous Velocipede

Trample
Each other Vehicle and creature you control enters with an additional +1/+1 counter on it if its mana value is 4 or less. Otherwise, it enters with three additional +1/+1 counters on it.
Crew 3

Amonkhet Raceway

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
{T}: Add {C}.
Max speed — {T}: Target creature gains haste until end of turn.

Defend the Rider

Choose one —
• Target permanent you control gains hexproof and indestructible until end of turn.
• Create a 1/1 colorless Pilot creature token with "This token saddles Mounts and crews Vehicles as though its power were 2 greater."

Twinblade Blessing

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Lagorin, Soul of Alacria

Flying
Whenever Lagorin attacks while saddled, put a +1/+1 counter on each of up to two target Mounts and/or Vehicles.
Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Costume Closet

This artifact enters with two +1/+1 counters on it.
{T}: Move a +1/+1 counter from this artifact onto target creature you control. Activate only as a sorcery.
Whenever a modified creature you control leaves the battlefield, put a +1/+1 counter on this artifact. (Equipment, Auras you control, and counters are modifications.)

Brightfield Glider

Vigilance
Whenever this creature attacks while saddled, it gets +1/+2 and gains flying until end of turn.
Saddle 3 (Tap any number of other creatures you control with total power 3 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Cloudspire Captain

Mounts and Vehicles you control get +1/+1.
This creature saddles Mounts and crews Vehicles as though its power were 2 greater.

Forest

Honor

Put a +1/+1 counter on target creature.
Draw a card.

District Mascot

This creature enters with a +1/+1 counter on it.
{1}{G}, Remove two +1/+1 counters from this creature: Destroy target artifact.
Whenever this creature attacks while saddled, put a +1/+1 counter on it.
Saddle 1

Bulwark Ox

Whenever this creature attacks while saddled, put a +1/+1 counter on target creature.
Sacrifice this creature: Creatures you control with counters on them gain hexproof and indestructible until end of turn.
Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Hemosymbic Mite

Whenever this creature becomes tapped, another target creature you control gets +X/+X until end of turn, where X is this creature's power.

Roadside Assistance

Enchant creature or Vehicle
When this Aura enters, create a 1/1 colorless Pilot creature token with "This token saddles Mounts and crews Vehicles as though its power were 2 greater."
Enchanted permanent gets +1/+1 and has lifelink.

Alacrian Armory

Creatures you control get +0/+1 and have vigilance.
At the beginning of combat on your turn, choose up to one target Mount or Vehicle you control. Until end of turn, that permanent becomes saddled if it's a Mount and becomes an artifact creature if it's a Vehicle.

Caradora, Heart of Alacria

When Caradora enters, you may search your library for a Mount or Vehicle card, reveal it, put it into your hand, then shuffle.
If one or more +1/+1 counters would be put on a creature or Vehicle you control, that many plus one +1/+1 counters are put on it instead.