Here is a fire sprite that I found on internet and converted to AoC format, this have 64 frames with loop animation, with the versions Fire, Smoke and mixed. Also have a psd file so you can edit this.
WARNING: Maybe i dont removed extra space on slp's frames, so you need to make it. Just click on "Crop blank pixels" option on SLP Editor with all frames selected, unselect "Auto selection mask" box.