Prizefight

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Overgrown Farmland

Overgrown Farmland enters tapped unless you control two or more other lands.
{T}: Add {G} or {W}.

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.

Copperline Gorge

Copperline Gorge enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Razorverge Thicket

Razorverge Thicket enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {W}.

Chandra's Magmutt

{T}: Chandra's Magmutt deals 1 damage to target player or planeswalker.

Leonin Warleader

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

Pack Leader

Other Dogs you control get +1/+1.
Whenever Pack Leader attacks, prevent all combat damage that would be dealt this turn to Dogs you control.

Spirited Companion

When Spirited Companion enters, draw a card.

Akoum Hellhound

Landfall — Whenever a land you control enters, Akoum Hellhound gets +2/+2 until end of turn.

Mountain

Plains

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.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. Battlefield Forge deals 1 damage to you.

Forest

Take Up the Shield

Put a +1/+1 counter on target creature. It gains lifelink and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)