This is a self-portrait taken by a crested black macaque who reportedly snatched a wildlife photographer's camera on the Indonesian island of Sulawesi. From The Telegraph:
David (Slater), 46, said: "One of them must have accidentally knocked the camera and set it off because the sound caused a bit of a frenzy.
"At first there was a lot of grimacing with their teeth showing because it was probably the first time they had ever seen a reflection.
"They were quite mischievous jumping all over my equipment, and it looked like they were already posing for the camera when one hit the button.
"The sound got his attention and he kept pressing it. At first it scared the rest of them away but they soon came back – it was amazing to watch.
"He must have taken hundreds of pictures by the time I got my camera back, but not very many were in focus. He obviously hadn't worked that out yet.