User blog comment:MetalShadow272/When Wacky Worlds Collide Volume 5/@comment-25685240-20120724210934/@comment-17720060-20120724211156

Kippy has the ability to shrink his tail to the point where it can't be seen, or extend his tail to the point where it's like a really, REALLY long rope. That explains why his tail can't be seen in some frames, and in others, his tail is shown, sometimes varying in sizes.