Why do people call the Bijuu "tailed beasts" if not all of them have tails?
As you can see in both of these pictures, the tails originate from the lower back of the beasts, where normally the tail would originate. 

For Gyūki, the limbs should be on the front or below the body to be considered limbs.

For Chōmei, the wings need to be higher up, up from the centroid, or the head would be below the rest of the body while using the wings.

Links to the original images:
Gyūki
Chōmei