A simple cat animation from data original sourced from an 1984 book called “Create Your Own - Games Computers Play” by Keith S. Reid-Green, on pages 57 - 58. I converted the code from GW-BASIC to ZX81 BASIC. Quite a bit different as the ZX81 doesn’t have DATA or READ commands.
JSZeddy, by Erik Olofsen based on JSSpeccy and Z81 emus.
For programs that don’t auto-run, press R then ENTER.
Also you may need to click on the applet to enable keyboard entry.