you made this plugin...

http://www.vendetta-online.com/x/msgboard/9/17115?page=3#229041

I have some PNGs that might look a little better. I tried to just replace the original ones but that just led to epic fail.

They need to be square aspect ratio 1:1. Spucks are 256x256, but they look a lil blocky at that low res, 512x512 looks better, and should still load fast enough on most systems, 1024x1024 might look best, but it may fail to load, or have issues with it looking crap if their system is too slow. Don't worry about losing the current 4:3 aspect ratio either, the Lua code stretches the images to full screen anyway, and they will look stretched on widescreen monitors nomatter what you do.

I like my animation!

Dunno what epically failed for you but those images seem to work here. I also just overwrote the original ones.
Resolution shouldn't matter as long as it's a multiple of 16. At 1024x768 each one will eat abvout 3mb of memory though..

Other things to keep in mind:
If you want to see the background you will have to reduce the alpha of the images and probably have to run them through the tool in this post: http://vendetta-online.com/x/msgboard/9/13370.
The path to the images and number of frames iis hardcoded. So always replace all images and don't rename the plugin directory.
Restart the game if you change the images. Something gets screwed up when you just do ReloadInterface().

Hm, it didn't work for me either by *just replacing the images* I did have to resize them. But realised that I was re-exporting the png's with similar rules to rays tool in gimp(so yes, any size works). So why it is working for you without a change is beyond me spuck. Maybe the link is to an old version?

Nah .. I always copy new versions over the old ones.

Maybe the size had to be a power of two not multiple of 16. I think it depends on the video drivers and OS. I never had problems with odd sized images but other computers seem to be pickier.