>>26319
Krita has a very basic animation timeline within. Theres a free animation program called Opentoonz. It has both vector and raster workflows but I have no experience how the rasters work in that one.

If you're not going for actual animation but just want to create a sequence of images with 2-3 seconds inbetween before it changes to another image, you can do that with editing programs like Premiere pro or After Effects, or whatever free versions of those are floating around.

Last but not least theres free browser GIF makers like ezgif: https://ezgif.com/