Some AnimGifs are not transparent:
import PIL.Image
with PIL.Image.open('/tmp/AnimGif.gif', 'r') as image:
for index, frame in enumerate(PIL.ImageSequence.Iterator(image)):
#frame = frame.convert('RGBA')
frame.save('/tmp/m/'+str(index)+'.png', 'PNG')
Image:

For example frame 6 and 19:

