This is not a SWF though, but actually injected code, that paints an image above the WoW login screen. Totally overkill.It is a sequence of images. Doing that via BLPs and writing LUA code in gluexml, you may be able to reproduce stuff like this.More complex stuff but showing image based animations will get harder.Using SWFs is not possible. Same for GIFs or whatever you come up with. BLP and AVI it is.