Nightmare
There is more than one artist with this name.
1) Nightmare, a Japanese visual rock band Naitomea, see ナイトメア.
2) Nightmare, a French heavy metal band.
3) Nightmare, a Japanese hardcore punk band.
4) Nightmare, an Italian progressive metal band.
5) Nightmare, a Serbian rapper.
6) Nightmare, a Polish thrash/speed metal band.
7) Nightmare, a Croatian rapper
8) Nightmare, a Colombian Heavy/Speed Metal band.
2) Nightmare is a heavy metal band from Grenoble