This applet draws a horizontal line that is periodically invaded by a shark. You can use the applet to spice up a web page:

Unfortunately, you don't have the Java language, so you can't see it work.

The source is here.

Ken Shirriff:
This page:
Copyright 2000 Ken Shirriff. Last updated 3/13/2001. Java and other Java-based names are trademarks of Sun Microsystems, Inc. and refer to Sun's family of Java-branded technologies. Use of this software is subject to the terms of the license agreement.