Go for Blood

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Cycling {1} ({1}, Discard this card: Draw a card.)

Pit Fight

Target creature you control fights another target creature. (Each deals damage equal to its power to the other.)

Giant Growth

Target creature gets +3/+3 until end of turn.

Hunger of the Howlpack

Put a +1/+1 counter on target creature.
Morbid — Put three +1/+1 counters on that creature instead if a creature died this turn.

Goblin Goon

Goblin Goon can't attack unless you control more creatures than defending player.
Goblin Goon can't block unless you control more creatures than attacking player.

Vulshok Morningstar

Equipped creature gets +2/+2.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Lord of Shatterskull Pass

Level up {1}{R} ({1}{R}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-5
6/6
LEVEL 6+
6/6
Whenever Lord of Shatterskull Pass attacks, it deals 6 damage to each creature defending player controls.

Aggressive Urge

Target creature gets +1/+1 until end of turn.
Draw a card.

Elephant Guide

Enchant creature
Enchanted creature gets +3/+3.
When enchanted creature dies, create a 3/3 green Elephant creature token.

Veteran Brawlers

Veteran Brawlers can't attack if defending player controls an untapped land.
Veteran Brawlers can't block if you control an untapped land.

Boggart Ram-Gang

Haste
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Omnath, Locus of Rage

Landfall — Whenever a land you control enters, create a 5/5 red and green Elemental creature token.
Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to any target.

Rootbound Crag

Rootbound Crag enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Kogla, the Titan Ape

When Kogla, the Titan Ape enters, it fights up to one target creature you don't control.
Whenever Kogla attacks, destroy target artifact or enchantment defending player controls.
{1}{G}: Return target Human you control to its owner's hand. Kogla gains indestructible until end of turn.

Domri Rade

+1: Look at the top card of your library. If it's a creature card, you may reveal it and put it into your hand.
−2: Target creature you control fights another target creature.
−7: You get an emblem with "Creatures you control have double strike, trample, hexproof, and haste."

Gruul Ragebeast

Whenever Gruul Ragebeast or another creature you control enters, that creature fights target creature an opponent controls.

Karplusan Yeti

{T}: Karplusan Yeti deals damage equal to its power to target creature. That creature deals damage equal to its power to Karplusan Yeti.

Turntimber Grove

Turntimber Grove enters tapped.
When Turntimber Grove enters, target creature gets +1/+1 until end of turn.
{T}: Add {G}.

Boxing Ring

Whenever a creature you control enters, it fights up to one target creature you don't control with the same mana value.
{T}: Create a Treasure token. Activate only if you control a creature that fought this turn.

Predatory Urge

Enchant creature
Enchanted creature has "{T}: This creature deals damage equal to its power to target creature. That creature deals damage equal to its power to this creature."

Arena

{3}, {T}: Tap target creature you control and target creature of an opponent's choice they control. Those creatures fight each other. (Each deals damage equal to its power to the other.)

Nightfall Predator

{R}, {T}: Nightfall Predator fights target creature. (Each deals damage equal to its power to the other.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Nightfall Predator.

Daybreak Ranger

{T}: Daybreak Ranger deals 2 damage to target creature with flying.
At the beginning of each upkeep, if no spells were cast last turn, transform Daybreak Ranger.

Daybreak Ranger // Nightfall Predator

Tahngarth, Talruum Hero

Vigilance
{1}{R}, {T}: Tahngarth, Talruum Hero deals damage equal to its power to target creature. That creature deals damage equal to its power to Tahngarth.

Ulvenwald Tracker

{1}{G}, {T}: Target creature you control fights another target creature.

Arni Slays the Troll

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Target creature you control fights up to one target creature you don't control.
II — Add {R}. Put two +1/+1 counters on up to one target creature you control.
III — You gain life equal to the greatest power among creatures you control.

Taiga

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Grifter's Blade

Flash
As Grifter's Blade enters, choose a creature you control it could be attached to. If you do, it enters attached to that creature.
Equipped creature gets +1/+1.
Equip {1}

Blighted Gorge

{T}: Add {C}.
{4}{R}, {T}, Sacrifice Blighted Gorge: It deals 2 damage to any target.

Goblin Psychopath

Whenever Goblin Psychopath attacks or blocks, flip a coin. If you lose the flip, the next time it would deal combat damage this turn, it deals that damage to you instead.

Hamletback Goliath

Whenever another creature enters, you may put X +1/+1 counters on Hamletback Goliath, where X is that creature's power.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Longstalk Brawl

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Choose target creature you control and target creature you don't control. Put a +1/+1 counter on the creature you control if the gift was promised. Then those creatures fight each other.

Alpha Brawl

Target creature an opponent controls deals damage equal to its power to each other creature that player controls, then each of those creatures deals damage equal to its power to that creature.