It's a bad sprite map; its graphics are not distributed proportionately. It needs to be broken down into equal sized tiles with one animation frame in each tile, which is not the case.
If you are comfortable with computer graphics work; then do the following.
1. Obtain the Gimp if you don't have Photoshop.
2. Create a new transparent background image or black background image, preferably 1024,1024 pixels in size to leave room for any future new frames. It does not have to be that size for 2D use, but is a good habit of using powers of 2.
3. Show the grid, adjust it in preferences/options. Set the grid size to 64 pixels.
4. If you want a transparent background, open the original sprite map and select the backdrop with the magic wand tool, double click the background layer or right click and convert into a layer. Then delete the backdrop.
4. Copy each frame into each grid tile on a seperate layer. Make sure anti-aliasing is active if you want transparency for better results. Keep each frame in seperate layers so you can easily move them around individually to tweak the animation.
Don't worry about the excess room, leave that for new animations.