Plains

Stonybrook Schoolmaster

Whenever this creature becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Novice Inspector

When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

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.)

Granite Witness

Flying, vigilance
Disguise {W/U}{W/U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this creature is turned face up, you may tap or untap target creature.

Dog Walker

Vigilance
Disguise {R/W}{R/W} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this creature is turned face up, create two tapped 1/1 white Dog creature tokens.

Sacred Peaks

({T}: Add {R} or {W}.)
This land enters tapped.

Interface Ace

This creature saddles Mounts and crews Vehicles using its toughness rather than its power.
Whenever this creature becomes tapped during your turn, untap it. This ability triggers only once each turn.

Village Bell-Ringer

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, untap all creatures you control.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Sunshot Militia

Tap two untapped artifacts and/or creatures you control: This creature deals 1 damage to each opponent. Activate only as a sorcery.