The Reaper is an Infected card in the "Alliance" expansion deck for Resident Evil: The Deck Building Game.
The Reaper's effect is very specific and in most circumstances may not apply to whichever player killed it. If the Reaper wasn't defeated from damage equal to its own health, then the player has to trash the highest costing card attached to their Partner Character. The only character who would seem to benefit from successfully matching their damage to the Reaper's health is Carlos Oliveira; who can move one card from his discard pile to his hand after he explores.
The Reaper has 35 Health, deals 40 Damage, and is worth 4 Decorations.