I made a fiddle for you, not sure why people are downvoting the question. This is just one solution, adding and removing a CSS class with display:hidden;. Click the picture to begin flashing, you can adjust the flashing speed by adjusting the 300 in the math.random variable, lower is faster.
http://jsfiddle.net/seano666/tDWme/1/
function flash(){
var del = Math.floor((Math.random()*300)+50);
$('#kitten').toggleClass("display").delay(del);
$('#kitten').promise().done(function(){
flash();
});
}
EDIT: Added some sound effects to the fiddle, good fun!