In their natural state, draft serpents are not particularly fast creatures, nor are they unusually powerful. Legged creatures such as anathaks would seem like a better choice to pull a vehicle. However, they have one advantage that sets them apart from all other beasts of burden: their natural form of locomotion closely resembles the type of motion one would use when wearing hoverskates. Since animals tend to rely on instinct for simple activities such as walking or running, no other animal can be easily trained to use hoverskates. The draft serpent, being the main exception, therefore has a significant advantage.
When used to pull a vehicle, the draft serpent has rows of hoverskates (or equivalent hoverpod assemblies) strapped to its belly. As the serpent slithers side to side, this lateral motion is converted into forward thrust. As a result, the serpent incurs no ground friction. The hovercart it pulls likewise generates no ground friction. The long, slender body of the serpent has little aerodynamic drag, and the drag of the vehicle can be reduced using a force bubble. Because a serpent-drawn vehicle has so little drag, they can go unusually fast even though the draft serpent itself is not an unusually powerful animal (for its size).
Draft serpents are generally considered omnivorous despite being derived from carnivorous species. That is to say, they can sustain their energy on starchy fruits rather than requiring a predominantly meat-based diet. However, they still require significant amounts of meat to sustain their health, and the plant matter they consume must contain digestible fats or carbohydrates; a draft serpent cannot eat grass like many herbivorous animals. This makes them much more expensive to maintain than other beasts of burden. This cost is justified only for situations in which their extra speed is essential.