pumba.swf is a screamer which was popularized by the French forum website jeuxvideo.com. When one clicks on the link, it downloads a file called puma.swf. After extracting it, a file called stream.mp3 is created. When you click onto it, a looping clip of Pumba from The Lion King is heard, accompained by a loud animal scream.
NOTE: The following website contains a screamer.