Photobomb

[Becky]

(verb)- to drop in a [photo] unexpectedly...to hop in a [picture] right before it is taken.

[PussyCat]

An otherwise normal photo that has been ruined or spoiled by someone who was not supposed to be in the photograph.

[Becky]

Any time the background of a picture hijacks the original focus.

[Couch Potatoe]

[The one] [innocent] thing you should NEVER say at an [airport].

[Greta]

to [jump in] a picture right before it is taken in [Ontario], Canada it is known as the [pop-in]

[Tanya Shivari]

[the explosion] of [tagged] pictures from multiple sources to a persons facebook [page] after an event.

[Gregory]

Spoil a photograph of (a person or thing) by unexpectedly appearing in the cameras field of view as the picture is taken, typically as a prank or practical joke.

[Sommer]

to appear behind or in front of someone when their photograph is being taken, usually doing something silly as a joke: