Feline Sovereign

Other Cats you control get +1/+1 and have protection from Dogs.
Whenever one or more Cats you control deal combat damage to a player, destroy up to one target artifact or enchantment that player controls.

Rin and Seri, Inseparable

Whenever you cast a Dog spell, create a 1/1 green Cat creature token.
Whenever you cast a Cat spell, create a 1/1 white Dog creature token.
{R}{G}{W}, {T}: Rin and Seri, Inseparable deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of Cats you control.

Keeper of Fables

Whenever one or more non-Human creatures you control deal combat damage to a player, draw a card.

Healer of the Pride

Whenever another creature you control enters, you gain 2 life.

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.

Skyhunter Patrol

Flying, first strike (This creature can't be blocked except by creatures with flying or reach, and it deals combat damage before creatures without first strike.)

Scythe Leopard

Landfall — Whenever a land you control enters, Scythe Leopard gets +1/+1 until end of turn.

Generous Stray

Felidar Sovereign

Vigilance (Attacking doesn't cause this creature to tap.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your upkeep, if you have 40 or more life, you win the game.

Sanctuary Cat

Leonin Warleader

Whenever Leonin Warleader attacks, create two 1/1 white Cat creature tokens with lifelink that are tapped and attacking.

Phantom Tiger

Phantom Tiger enters with two +1/+1 counters on it.
If damage would be dealt to Phantom Tiger, prevent that damage. Remove a +1/+1 counter from Phantom Tiger.

Spirit of the Hearth

Flying
You have hexproof. (You can't be the target of spells or abilities your opponents control.)

Immolating Souleater

{R/P}: Immolating Souleater gets +1/+0 until end of turn. ({R/P} can be paid with either {R} or 2 life.)