Grim is a sinister four letter word.
I had always thought that the word "grim" actually comes from the Grimm Brothers, whose original fairy tales always seemed to be filled with horrific actions, dismal fates, and sinister villains. It turns out, however, that it comes from the Middle English for fierce or severe.
Still, the Grimm tales are sometimes so horrible that, even when cleaned up by Walt Disney, they can be considered too frightening for young children. The _Snow White_ ride at Walt Disney World contains a warning that the Evil Queen may be too intense. Even during their lifetime, the Grimm brothers edited their works in subsequent printings to make the tales more child-friendly... while still keeping the strict moral lessons they wished to impart.
And two hundred years on, they still contain moral lessons for children and adults.