Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Claws Out

This spell costs {1} less to cast for each Cat you control.
Creatures you control get +2/+2 until end of turn.

Dawnwing Marshal

Flying
{4}{W}: Creatures you control get +1/+1 until end of turn.

Leonin Vanguard

At the beginning of combat on your turn, if you control three or more creatures, this creature gets +1/+1 until end of turn and you gain 1 life.

Requisition Raid

Spree (Choose one or more additional costs.)
+ {1} — Destroy target artifact.
+ {1} — Destroy target enchantment.
+ {1} — Put a +1/+1 counter on each creature target player controls.

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Regal Caracal

Other Cats you control get +1/+1 and have lifelink. (Damage dealt by those creatures also causes you to gain that much life.)
When this creature enters, create two 1/1 white Cat creature tokens with lifelink.

Lay Down Arms

Exile target creature with mana value less than or equal to the number of Plains you control. Its controller gains 3 life.

Plains

Skyknight Squire

Whenever another creature you control enters, put a +1/+1 counter on this creature.
As long as this creature has three or more +1/+1 counters on it, it has flying and is a Knight in addition to its other types.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on this creature.

Prideful Parent

Vigilance (Attacking doesn't cause this creature to tap.)
When this creature enters, create a 1/1 white Cat creature token.

Hinterland Sanctifier

Whenever another creature you control enters, you gain 1 life.

Elspeth's Smite

Elspeth's Smite deals 3 damage to target attacking or blocking creature. If that creature would die this turn, exile it instead.

Market Gnome

When Market Gnome dies, you gain 1 life and draw a card.
When Market Gnome is exiled from the battlefield while you're activating a craft ability, you gain 1 life and draw a card.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Roaming Throne

Ward {2}
As Roaming Throne enters, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.