Sarn Riders are involved in events in Warlock of the Witch World
Appearance: Though mentioned in many books and stories the exact appearance of a Sarn Rider tends not to be covered. Mostly because they tend to keep their features covered by helmets and hoods and seem to shun direct sunlight. Their very presence causes unease in people.
Life Span: It's not known how long a Sarn Rider lives.
Power: Sarn Riders do not tend to demonstrate Power overtly. That they might not have Power seems improbable. They have been seen to wield whips of black lightning, similar but opposite to the weapons of the Green People.
Other: Sarn Riders are creatures of the Dark. Though they once took Keplian mounts they now seem to ride on lizard-like mounts mainly. Songsmith seems to introduce an equivalent that rides in Arvon that is not necessarily of the Dark, but might serve it.
The lizard horses in Songsmith are described as having long, narrow heads, necks, bodies, and legs. They have smooth, white to grey-scaled skins and sharp, curving teeth. Instead of hooves they have clawed talons. Their tails are not mentioned, but since they resemble a cross between a lizard and a horse, they could well have a lizard-like tail.