Slurrk, All-Ingesting

Slurrk, All-Ingesting enters with five +1/+1 counters on it.
Whenever Slurrk or another creature you control dies, if it had a +1/+1 counter on it, put a +1/+1 counter on each creature you control that has a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature of their choice.

Snow-Covered Swamp

Corpse Churn

Mill three cards, then you may return a creature card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Forest

Elvish Visionary

When Elvish Visionary enters, draw a card.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Elvish Doomsayer

When Elvish Doomsayer dies, each opponent discards a card.

Entourage of Trest

When Entourage of Trest enters, you become the monarch.
Entourage of Trest can block an additional creature each combat as long as you're the monarch.

Murder

Scaled Behemoth

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Ordeal of Nylea

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice this Aura.
When you sacrifice this Aura, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Falthis, Shadowcat Familiar

Commanders you control have menace and deathtouch.
Partner (You can have two commanders if both have partner.)

Fin-Clade Fugitives

Fin-Clade Fugitives can't be blocked by creatures with power 2 or less.
Encore {4}{G} ({4}{G}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Haunted Cloak

Equipped creature has vigilance, trample, and haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Lys Alana Bowmaster

Reach
Whenever you cast an Elf spell, you may have Lys Alana Bowmaster deal 2 damage to target creature with flying.

Undergrowth Stadium

Undergrowth Stadium enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Maalfeld Twins

When this creature dies, create two 2/2 black Zombie creature tokens.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Farhaven Elf

When Farhaven Elf enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sengir, the Dark Baron

Flying
Whenever another creature dies, put two +1/+1 counters on Sengir, the Dark Baron.
Whenever another player loses the game, you gain life equal to that player's life total as the turn began.
Partner (You can have two commanders if both have partner.)

Fertilid

Fertilid enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Spark Harvest

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Destroy target creature or planeswalker.

Dawnglade Regent

When Dawnglade Regent enters, you become the monarch.
As long as you're the monarch, permanents you control have hexproof.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Ambush Viper

Ivy Lane Denizen

Whenever another green creature you control enters, put a +1/+1 counter on target creature.

Terramorphic Expanse

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

Feast of Succession

All creatures get -4/-4 until end of turn. You become the monarch.

Bladebrand

Target creature gains deathtouch until end of turn.
Draw a card.

Moss Diamond

Moss Diamond enters tapped.
{T}: Add {G}.

Armory of Iroas

Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)