Implicating nightmare -> dream.

Reason:

Wyvrn said:
Implicating nightmare -> dream.

Reason:

No, nightmare is not only a dream. For example:
post #167592

The accepted definition of nightmare is a kind of dream. If an artist chooses to call their species of scary horses "nightmares" it doesn't change the definition of the word.

Honestly I'm not even sure that picture should be tagged "nightmare". All I see is a demonic horse with a fiery mane, calling it a nightmare is totally subjective.

http://en.wikipedia.org/wiki/Mare_%28folklore%29

Words sometimes have more than one definition.

According to that page, the "mare" in "nightmare" is a goblin that sits on people's chest while they sleep, nothing to do with fiery horses at all.

Oops, fail from my side. But nightmarish looking horse is commonly associated with name of nightmare.
Like in D&D or even searching "nightmare horse" in google graphics. I don't know why is it so commonly associated, so I thought that the folk tale was a reason, and didn't read wikipedia page before posting.

Nightmare being a dream is the prevailing usage, but I see that there are a few pictures that do use it as a species. I propose that these be retagged to "nightmare_(species)" and that "nightmare" be reserved just for horrifying dreams. Then there'd be no problem.

Wyvrn said:
Nightmare being a dream is the prevailing usage.

From what I see in nightmare most cases of this tag are tagging failures from either nightmare_moon or nightmare_fuel. And remaining minority is divided about equally to a dream, and an horse.

The usual standard on a site like this would be to do something like "nightmare_(species)".

There, cleaned up the nightmare tag. A lot of things went to horror or nightmare_fuel, a lot of things went to nightmare_(species), a few things went to nightmare_moon_(mlp), and a surprising number of things went to nightmare_(character). All thats left are the bad dreams, and this implication is ready to be applied.