“Photobombing” is the age-old practice of sneaking into the background and making a funny face while someone takes a photo, usually (but not always) of a group of people. I’m sure you know what I mean, but just in case you don’t, you can see some pretty funny examples here.
But here’s one photobomb that’s both funny and scary:
I, for one, wouldn’t want Mike Tyson sneaking up on me like that!
(Originally seen on nextround.net)