Mountain

Tiger-Dillo

This creature can't attack or block unless you control another creature with power 4 or greater.

Mongoose Lizard

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, it deals 1 damage to any target.
Mountaincycling {2} ({2}, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

Firebending Lesson

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Firebending Lesson deals 2 damage to target creature. If this spell was kicked, it deals 5 damage to that creature instead.

Fang, Roku's Companion

Flying
Whenever Fang attacks, another target legendary creature you control gets +X/+0 until end of turn, where X is Fang's power.
When Fang dies, if he wasn't a Spirit, return this card to the battlefield under your control. He's a Spirit in addition to his other types.

Komodo Rhino

Trample (This creature can deal excess combat damage to the player it's attacking.)

Powerful

Fire Nation Raider

Raid — When this creature enters, if you attacked this turn, create a Clue token. (It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Uncle Iroh

Firebending 1 (Whenever this creature attacks, add {R}. This mana lasts until end of combat.)
Lesson spells you cast cost {1} less to cast.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Freedom Fighter Recruit

Freedom Fighter Recruit's power is equal to the number of creatures you control.

Hog-Monkey Rampage

Choose target creature you control and target creature an opponent controls. Put a +1/+1 counter on the creature you control if it has power 4 or greater. Then those creatures fight each other. (Each deals damage equal to its power to the other.)

How to Start a Riot

Target creature gains menace until end of turn. (It can't be blocked except by two or more creatures.)
Creatures target player controls get +2/+0 until end of turn.

Combustion Man

Whenever Combustion Man attacks, destroy target permanent unless its controller has Combustion Man deal damage to them equal to his power.