The "Smile Dog" is a fictional supernatural entity which was the focus of the story Smile.jpg - which grew into an internet meme.
Appearance
Smile Dog is believed to be a demonic creature resembling a grinning dog which appears in a photograph, when it is viewed by an individual, the victim will be plagued by tormenting and traumatizing nightmares. These dreams will always feature of the Smile Dog. In it, the victim will usually ask what it wants. To which it replies with it's famous line "Spread the word". What he means by this is that he's asking (or, to put it bluntly, blackmailing) that they attach the file and send it to other people. Deleting or simply not viewing the picture will result in the same thing. If Smile Dog's wish is not granted after three days, the picture will mutate and deform, depicting a much more disturbing and demonic form of Smile Dog (which many fans and theorists have depicted as Smile Dog's True Form). Thus, amplifying his already terrifying powers to a demonic new level. And worsening the nightmares of his victims just as much.
Smile Dog is very persistence in it's goals; able to continue psychologically torment and haunt it's victim(s) in their dreams for months (or even years) until they either "spread the word" or they commit suicide (the latter happening much more often). Or they will simply try to avoid sleeping, resulting in death from sleep deprivation and malnourishment (which may be caused by the victim's extreme fear to make them disinterested in it). In some variations of the story, after an extremely long period of resistance, Smile Dog will finally manifest into the real world and will haunt and plague the victim in the real waking world as well as their dream world. If the victim continues to resist, after an extremely long time enough to wear down Smile Dog's patience, he will finally manifest into the real world and finally end the victim's suffering, by viciously, and painfully killing them. And, even further, one story even mentions Smile Dog dragging the souls of his victims down to hell with him.
There are some who say, that the origins of Smile Dog come from an original picture of himself.
