One of the recreational uses for terminals included creating animations by typing in reams of text and escape sequences that positioned text at various places on the screen. By sending these files to the terminal, moving characters would be seen. The timing of the animation is dependent on the speed of the serial line going to the terminal. For this reason, these files do not work well on terminal emulators with telnet connections.
As a very unseasonal introduction, here are some Christmas animations donated by Peter Weaver. I have no idea how old some of these are, or who the original authors were.
Peter has also written a DCL script, random_xmas.com to display these under VMS.