Daemogoth Titan

Whenever this creature attacks or blocks, sacrifice a creature.

Daemogoth Woe-Eater

At the beginning of your upkeep, sacrifice a creature.
When you sacrifice this creature, each opponent discards a card, you draw a card, and you gain 2 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."

Shadowheart, Dark Justiciar

{1}{B}, {T}, Sacrifice another creature: Draw X cards, where X is that creature's power.
Choose a Background (You can have a Background as a second commander.)

Gluttonous Troll

Trample
When this creature enters, create a number of Food tokens equal to the number of opponents you have. (Food tokens are artifacts with "{2}, {T}, Sacrifice this token: You gain 3 life.")
{1}{G}, Sacrifice another nonland permanent: This creature gets +2/+2 until end of turn.

Ravenous Squirrel

Whenever you sacrifice an artifact or creature, put a +1/+1 counter on this creature.
{1}{B}{G}, Sacrifice an artifact or creature: You gain 1 life and draw a card.