Of the remainder of the skeleton only the tail had been prepared in 2017.
The tail has a total length of 278 centimetres (109 in).
The tail is divided into "free" front caudal vertebrae of the base and a "tail club" at the rear.
In the latter organ Coombs distinguished again a "handle" and a "knob".
The tail club, including the handle, has a length of 210 centimetres (83 in), a record among North American ankylosaurids.

In the handle, thirteen vertebrae are present.
Probably another three are covered by the knob.
To increase the chance of a damaging plastic deformation on impact of the knob, the handle is a stiff structure, the lack of flexibility caused by special connections between the vertebrae.
The paired front joint processes, the prezyapophyses, are strongly elongated and overlap half of the preceding vertebra.
They form a V-like structure, the branches angled at about 20°.
Their joint facets are rotated to above and embrace the neural spine of the preceding vertebra.
This spine is wedge-shaped and bent to behind with a flat top surface to fit into the V. This way a series of interlocking connections is formed, covering the entire top surface of the handle.
The handle is further stiffened by bundles of ossified tendons, closely appressed to the vertebral sides.
The tendons are over 50 centimetres (20 in) long and 5–8 mm (0.20–0.31 in) in diameter, with tapering ends.

Along the sides of the handle runs a series of five pairs of osteoderms.
Zuul is the first American ankylosaurid in which such handle osteoderms have actually been discovered; they had only been assumed for other species.
On the free vertebrae of the tail base another three pairs are present.
Between the large osteoderms smaller ossicles are positioned.
The side tail osteoderms are flattened and have a triangular profile in top view, with a sharp point.
Those more at the front have a sharper point, being longer than wide.
They are almost shaped as an equilateral triangle with straight front and rear edges.
More to behind the triangles are lower and wider.
From the fifth pair onwards the front edges become longer and strongly concave, off-setting the point to the rear.
The last pair, immediately before the knob, is strongly rounded.

The front three side osteoderm pairs are covered by a black film that could be the remnant of their original keratin sheaths.
If so, these added 1–2 centimetres (0.39–0.79 in) to their length.
The sheaths show clear grooves and ridges directed towards the point.
At the left osteoderm of the third pair, a layered structure is visible at its base, resembling the construction of horn bases in bovids.
At the rear osteoderms, the film covering is incomplete, showing that the underlying bone structure does not conform to the sheath riles as it is much smoother.

The knob is relatively large with a length of 52.5 centimetres (20.7 in), a width of 36.8 centimetres (14.5 in), and a vertical height of 8 centimetres (3.1 in).
The bulk of the knob is formed by a pair of large osteoderms, each positioned at the side.
In the holotype individual, the left side osteoderm is distinctively longer than the right one, giving the knob as whole a rather asymmetrical profile.
This osteoderm also overlaps the last left triangular spike.
The general profile of the knob is oval as spikes or keels are lacking.
The side osteoderms almost touch each other at the top surface; at the underside a midline hiatus is present.
At the rear of the knob, a cluster of small osteoderms is positioned.
The outer corners of this cluster are formed by two trapezium-shaped elements.
The very rear is formed by a covering triangular midline osteoderm.
As a whole, the rear cluster has a straight posterior edge in top view.
The bone tissue of the knob has a sponge-like texture with many pits.

Apart from these bony structures, the tail also preserves non-bony scales.
These are not skin impressions but remains of the keratin skin tissue itself.
Such fossil scale remains are exceedingly rare.
In between the third pair of tail osteoderms a transverse row of five large scales is
Of the remainder of the skeleton only the tail had been prepared in 2017. The tail has a total length of 278 centimetres (109 in). The tail is divided into "free" front caudal vertebrae of the base and a "tail club" at the rear. In the latter organ Coombs distinguished again a "handle" and a "knob". The tail club, including the handle, has a length of 210 centimetres (83 in), a record among North American ankylosaurids.
In the handle, thirteen vertebrae are present. Probably another three are covered by the knob. To increase the chance of a damaging plastic deformation on impact of the knob, the handle is a stiff structure, the lack of flexibility caused by special connections between the vertebrae. The paired front joint processes, the prezyapophyses, are strongly elongated and overlap half of the preceding vertebra. They form a V-like structure, the branches angled at about 20°. Their joint facets are rotated to above and embrace the neural spine of the preceding vertebra. This spine is wedge-shaped and bent to behind with a flat top surface to fit into the V. This way a series of interlocking connections is formed, covering the entire top surface of the handle. The handle is further stiffened by bundles of ossified tendons, closely appressed to the vertebral sides. The tendons are over 50 centimetres (20 in) long and 5–8 mm (0.20–0.31 in) in diameter, with tapering ends.
Along the sides of the handle runs a series of five pairs of osteoderms. Zuul is the first American ankylosaurid in which such handle osteoderms have actually been discovered; they had only been assumed for other species. On the free vertebrae of the tail base another three pairs are present. Between the large osteoderms smaller ossicles are positioned. The side tail osteoderms are flattened and have a triangular profile in top view, with a sharp point. Those more at the front have a sharper point, being longer than wide. They are almost shaped as an equilateral triangle with straight front and rear edges. More to behind the triangles are lower and wider. From the fifth pair onwards the front edges become longer and strongly concave, off-setting the point to the rear. The last pair, immediately before the knob, is strongly rounded.
The front three side osteoderm pairs are covered by a black film that could be the remnant of their original keratin sheaths. If so, these added 1–2 centimetres (0.39–0.79 in) to their length. The sheaths show clear grooves and ridges directed towards the point. At the left osteoderm of the third pair, a layered structure is visible at its base, resembling the construction of horn bases in bovids. At the rear osteoderms, the film covering is incomplete, showing that the underlying bone structure does not conform to the sheath riles as it is much smoother.
The knob is relatively large with a length of 52.5 centimetres (20.7 in), a width of 36.8 centimetres (14.5 in), and a vertical height of 8 centimetres (3.1 in). The bulk of the knob is formed by a pair of large osteoderms, each positioned at the side. In the holotype individual, the left side osteoderm is distinctively longer than the right one, giving the knob as whole a rather asymmetrical profile. This osteoderm also overlaps the last left triangular spike. The general profile of the knob is oval as spikes or keels are lacking. The side osteoderms almost touch each other at the top surface; at the underside a midline hiatus is present. At the rear of the knob, a cluster of small osteoderms is positioned. The outer corners of this cluster are formed by two trapezium-shaped elements. The very rear is formed by a covering triangular midline osteoderm. As a whole, the rear cluster has a straight posterior edge in top view. The bone tissue of the knob has a sponge-like texture with many pits.
Apart from these bony structures, the tail also preserves non-bony scales. These are not skin impressions but remains of the keratin skin tissue itself. Such fossil scale remains are exceedingly rare. In between the third pair of tail osteoderms a transverse row of five large scales is
Zuul