Mercenary Serpent Riders

What’s scarier than a Sand Serpent? A trained and experienced mercenary solider riding atop said serpent, ready to relentlessly pierce their foe’s flesh with their polearm. Those that agree to ride atop these gigantic snakes are a special breed of brave, or just outright insane. Either way they are a skilled and deeply coveted corps of individuals that are unmatched by any other riders in the Dead Sands. They are a special kind of ‘monster cavalry’ that use the fangs and poison of their mount in conjunction with their weapon to create devastating combos against a foe. It takes many years to learn how to ride a serpent and many more to master it, assuming that’s possible at all. 
Wild Sand Serpents are difficult enough to tame as it is, let alone allowing a rider, so serpents must be comfortable with and imprinted on their riders from birth. This means that only the most experienced and loyal mercenaries will ever be given the opportunity. Those chosen must be brave or mad enough to ride and live with such dangerous creatures, simply bailing out halfway through is not an option.
== Variants ==
Though they serve the same general purpose, some units in a country's military are given different equipment, in order to serve slightly different functions in the overall army. The severity and size of these differences varies on a case-by-case basis. Some units are given only slightly different weapons, whereas others are given new and unique technology.
=== Spearmen ===
Spear riders wield a long spear and shield into battle, atop their serpentine mount. They are an excellent well-rounded shock force, brutalising enemy ranks with fang and venom and spear. Their noxious venom can melt and weaken entire divisions, with the survivors being mopped up easily with the stabbing weapons of the mount and its rider. They will sometimes be deployed in groups, though this is very rare, in which their already incredibly destructive power becomes even more devastating. When facing a group of these monsters, there is no hope for survival.
=== Halberdiers ===
Halberd serpent riders go into battle wielding khopesh halberds, ditching the shields that their spear counterparts carry. Though this makes them more susceptible to ranged attacks, it is necessary for them to effectively wield their large polearms from their mounts. The chopping and slashing power of their polearms, combined with their deadly snake mounts, make them perfect for countering enemy cavalry and monsters. The Sand Serpent can trap the target with its deadly coil before finishing it off with fangs and polearms. Indeed, each one of this deadly duo is compelled to acts of great brutality - and will more than happily do so.