Grimm Reaper is the embodiment of Death itself. She takes joy in reaping ponies'
souls from their bodies, and she especially enjoys getting rid of ponies who hurt other ponies. Grimm is never seen, but always talked about, the tall skeletal pony enjoying the element of surprise. But when Twilight accidentally summons Death herself, what is the skeleton to do? She does have a list of ponies to die, and it's always a tight one.