Essence Channeler is a rare Creature — Bat Cleric card from Bloomburrow Promos (PBLB), collector number 12p. Current market price: $1.53 (foil $2.52), TCGplayer market prices via Scryfall.
As long as you've lost life this turn, this creature has flying and vigilance. Whenever you gain life, put a +1/+1 counter on this creature. When this creature dies, put its counters on target creature you control.