The Blood Mist

At the beginning of each player's upkeep, that player sacrifices a non-token creature they control. Put X Feeding counters on The Blood Mist where X is the sacrificed creature's power. Then, if there are no non-token creatures, create a red elemental avatar token creature with power and toughness each equal to the number of Feeding counters on The Blood Mist.
"Hunger itself shall feast upon you."