There are at least four different artists under this name:
1) a black metal band from Quebec, formely known as Niflheim.
They released two full length to date:
Il Était Une Forêt... in 2007 and À L'âme Enflammée, L'äme Constellée... in 2013.
For more info see http://www.myspace.com/niflheim5
2) a German rapper called Gris http://www.grismusik.de.
3) a Finnish band making jazz related music http://www.grismusique.com.
4) a alternative rock band from Argentina http://www.grisrock.com.ar.


Read more about Gris on Last.fm.