Grim Reapers are a neutral party of soul-gatherers in the anime and manga of Black Butler. Even though it is specified that they are neutral, they can be viewed as antagonists since they repeatedly attack the series' protagonists, Sebastian Michaelis and his young master Ciel Phantomhive.
The Grim Reapers in the Black Butler/Kuroshitsuji series resemble caucasian humanoid males, though there is a possibilty that some may be women, that dress mostly in black suits. Grim Reapers are horribly near-sighted so all of them wear spectacles to be able to see. Undertaker is an exception, but as a retired/deserted Reaper he no longer has much need for his glasses.
Each Grim Reaper has a Death Scythe to reap souls and sever them from the human's memories, thus permanently ending their life. Nearly every Grim Reaper's Scythe resembles a gardening tool: Grell Sutcliff's is a chainsaw, William's a pruner, and Ronald's a gas-powered lawnmower. Undertaker's seems to be another exception, since his looks exactly like a archetype Scythe.
- For nearly a decade after the series had began, it remained a mystery on what the Grim Reapers were really are until eventaully they were revealed to be Humans who had commited suicide and forced to become Grim Reapers as punishment.