Corpses are in no short supply.
Corpse Eater is a Sigil which causes a card to be automatically played in the place of the first of the player's cards to perish by combat. The effect requires the card bearing this sigil to be in the player's hand.
Strategy[]
If a creature that you own perishes by combat, a card bearing this sigil in your hand is automatically played in its place.
In Battle[]
Corpse Eater is a simple Sigil to use in that as soon as any player card of perishes during the combat phase, the card bearing this Sigil will jump from the player's hand to replace it. This ignores the cost of the card - no Bones are consumed and no sacrifices are necessary.
If a card perishes while attacking and a card bearing Corpse Eater is played in its place, the card bearing Corpse Eater will perform any remaining attacks that the original card would have performed. That is, if a card with Bifurcated, Trifurcated or Double Strike strikes a card with Sharp Quills, killing itself in the process, the Corpse Eater card will be played in its place and perform any attacks the previous card had yet to perform, using the Corpse Eater card's damage value.
Interestingly, the effect of the Prospector's pickaxe attack can be mitigated with this Sigil. When the Prospector strikes a card with the pickaxe, a card bearing Corpse Eater will be played in place of the killed card before a Gold Nugget can replace it.
Deckbuilding[]
Ideally, this Sigil should be placed onto powerful high cost cards to achieve the biggest result, such as a Grizzly or an Urayuli. However, Corpse Eater does have some more niche strategy effects when combined with other Sigils, as almost any Sigil works well alongside it - except for Brood Parasite, which has its effect negated.
Sigils with effects that trigger when a card is played, such as Fecundity and Rabbit Hole, are still triggered when a card is played this way. This can be used as an advantage in obtaining cards before the draw phase. Combining Fledgling and Corpse Eater means that a card played during the opponent's attack phase will instantly evolve at the start of the next turn, bypassing the need to wait. If combined with Unkillable, as soon as the card is killed it will immediately place itself back on the board after returning to the hand.