OK.. anytime you need to resize a gif image (animation) use gifwork. com and follow the easy instructions there. This gifwork site is specifically
for resizing animated gifs. You can't resize gifs in regular resizing places.
Hope that helps ! In gifworks, go to the left top of the page where it says "file".. click on that, then click on "file open"... you'll see two places you can upload.. one directly from a place in your pc (my pictures, etc.) or you can use the lower left box to upload the URL (http://)
which is what I used from the properties of your pic from the site where you got it.
After you do that, click fetch image. It will upload your piccy. Then click "edit". Choose resize. A new box will open and you put in your new size (100X100) or whatever as long as it's 100 or less on both sides. Make sure the keep constraints box is checked and it will do the rest. Then click OK in that little box up there.
Your new, resized ANIMATED gif will appear. Right click on it and save to your pc now in "my pictures" or wherever, and now you can do the avi thing as usual. Voila !