Otis the Grinning Hippo
When Jay Parker told his wife Lauren to say cheese, it seems someone else was listening, too. Otis the hippo pressed his face against the glass of his tank and produced what appears to be a beaming smile.
And when the couple exchanged positions, the three-ton beast duly obliged with another grin. The Parkers, from Little Rock, Arkansas, took their extraordinary photographs during a holiday visit to San Diego Zoo in California.
'Actually the week we were there the zoo had just put two hippos together for the first time in the tank.
'Hippos are not usually that friendly and the two they had in the tank - the male Otis and the female Funani - had been having a bit of a fight with each other that day.
'The hippo behind me is Otis, when we saw his face we just thought we had to get a picture.'
Mr Parker said he wasn't sure if Otis was happy or not after his day's ordeal with Funani - in fact he might even have been asleep.
He said: 'If you look at Otis's back you can see the scaring from his fight with Funani, this is normal hippo behaviour but I don't think he won.'
To add another dimension to the memorable snap, the picture has become something of an internet hit and pops up on blogs and chatrooms from USA to China.
Mr Parker, 35, from Little Rock, Arkansas, even gets fan mail from people telling him he is their computer screensaver or Facebook profile picture.
He said: 'It's kind of strange to think there are people out there with a picture of me on their computer, but I guess I'm just the hippo man as far they're concerned.