To find an animated picture on  your topic, in Google image search, type the word animated and anything you like! 
                                                                                                   frog, robot, tree.. etc.)
           or if you see one you like on a web site, right mouse click, and select 'save picture as...', 
          and save it to your folder where all of your web page picture files are going.

Then on your web page, go File /Inset Picture.../ from file, (the same as in MS Word), 
          and 'Browse' to select the animated picture in your folder.

Place it where you want and then click save. 

It will be animated when you close FrontPage and look at your page in a web browser, like Internet Explorer.