You've found the perfect setting to take a photo, you pull your best pose and put on your widest smile only for someone or something to suddenly loom into the background (or foreground!) just as the shutter's pressed!
Fortunately most photobombs create hilarious results and can even turn the subject into an internet sensation... From famous faces to cheeky animals, here's a selection of perfectly-timed snaps that are guaranteed to put a smile on your face!
1. A flying iguana!
2. Lurking beneath the depths...
3. Don't mess with Mother Nature
4. They won't forget this vacation in Rio!
5. Time for a good roll on the lawn
6. What's more, the photographer focused on the guy in the background
7. Do you think she realized that Nicolas Cage was behind her?
8. When a horse doesn't agree with an arrest warrant
9. A memorable dive...
10. That'll teach it to leave its tail dangling...
11. Hilarious canine photobomb
12. "I believe I can fly..."
13. Incoming attack!
14. Someone's jealous
15. That's quite a mouthful!
16. When your dog's determined to take center stage
17. Stunning butterfly!
18. When a photographer gets distracted
19. Someone's feeling left out...