Blood Pet

Augur of Skulls

{1}{B}: Regenerate this creature.
Sacrifice this creature: Target player discards two cards. Activate only during your upkeep.

Blood Vassal

Brindle Boar

Sacrifice this creature: You gain 4 life.

Cloakwood Hermit

Commander creatures you own have "At the beginning of your end step, if a creature card was put into your graveyard from anywhere this turn, create two tapped 1/1 green Squirrel creature tokens."

Bloodthrone Vampire

Sacrifice a creature: This creature gets +2/+2 until end of turn.

Abyssal Gatekeeper

When this creature dies, each player sacrifices a creature of their choice.

Viconia, Drow Apostate

At the beginning of your upkeep, if there are four or more creature cards in your graveyard, return a creature card at random from your graveyard to your hand.
Choose a Background (You can have a Background as a second commander.)

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on this creature.

Bottle Gnomes

Sacrifice this creature: You gain 3 life.

Chain Devil

Animate Chains — When this creature enters, each player sacrifices a nontoken creature of their choice.

Carrier Thrall

When this creature dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this token: Add {C}."

Accursed Marauder

When this creature enters, each player sacrifices a nontoken creature of their choice.

Cauldron Familiar

When this creature enters, each opponent loses 1 life and you gain 1 life.
Sacrifice a Food: Return this card from your graveyard to the battlefield.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Accursed Centaur

When this creature enters, sacrifice a creature.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Basal Thrull

{T}, Sacrifice this creature: Add {B}{B}.

Carrion Feeder

This creature can't block.
Sacrifice a creature: Put a +1/+1 counter on this creature.