When 8 'r's just doesn't cover it.
Naturally accompanied by shifty, evil eyes. Or when arguing with the dog over the last beef jerky.
Psycho: I shall rule the world
Jesus: I shall stop you!
Psycho: grrrrrrrrr (squints eyes and stares, dramatic music plays in background)
Dog: Woof Woof
Used to describe a person who is too beautiful, words can not describe his/her beautifulness.
Sometimes can be mistaken for an angry grrrrrr.
"He is just to Grrrrrrrrr"
"I wonder who is Grrrrrrrrr-ier, Harry or Zayn?"