The S'sssksskss are a sample alternate race for this setting, a reptilian race whose ancestors (which were at that point about the size of rats) survived the extinction of the dinosaurs. For some reason the mammals died out around that time (their scientists believe that they were wiped out by some contaminent thrown up by an asteroid impact, possibly water-borne bacteria) so the eventual winners in the evolutionary battle were mostly reptiles. They look vaguely like large iguanas, on average about 6ft 6in tall, with their tails used to stabilise their upright posture.
They're omnivores living on a mixture of vegetables, fruit, and invertebrate foods such as worms (they breed nearly two hundred subtly different species, each with its own unique taste), slugs, and snails. They mostly don't particularly like meat or fish but can eat them if they have to; they think of them as exotic foods, not as staples. They bear their children live, in clutches of two or three (very rarely one or four), and rear them much in the way that humans do, except that initially they chew food for their infants until their teeth develop. It's believed that the resultant puree contains useful bacteria and antibodies which colonise the bodies of the young and improve their health; young fed on prepared pureed foods are less healthy. Population density in their cities is a little higher than for humans, with an emphasis on tall residential towers, but there are still occasional villages, loners, etc., since they are as varied as humans.
Although they are sometimes described as cold blooded (the technical term is poikilothermic, obtaining warmth from their surroundings) they are almost always warm to the touch. They gain body heat from the sun and heat sources such as fires, warm lamps, etc., and in the last few hundred years from electrically-heated clothing. They believe that the initial spur to their intelligence was the struggle to find warmth during an ice age. They think that they've been intelligent fire-users for about two million years, with most historical records beginning about thirty thousand years ago and the scientific method developed about three thousand years ago. They're considerably more advanced than the average Victorian/Edwardian scientist in most areas of science; the main field that is lagging is astronomy, possibly because they have poorer night vision than humans and find the stars less interesting. Their senses of hearing and smell are very acute, and their arts reflect this, with incredibly complex music and rich "smell panoramas" commonplace.
In their native world and time there are at least twenty distinct S'sssksskss nations, all of which seem to have rapidly-changing borders and are primarily associations based on mutual interests, each with its own language and traditions. There is as much variation between S'sssksskss as there is between humans, and their cultures range from pacifist monks (yes, they do know lethal self-defence techniques) to heavily-armed military dictatorships. Nearly all S'sssksskss change nation several times in a lifetime of two to three hundred years, and they are very good at learning languages, down to the original speaker's accent. Once part of a nation (or even when visiting it for an extended period) they adopt its customs, clothing, language, etc., going "native" so far as it doesn't conflict with their personal beliefs. If there is a real conflict of interest they will usually leave, rather than fighting or trying to buck the local system, but will certainly fight if they have to. Few S'sssksskss would dream of stopping them. They will typically pick up human languages and habits in a few days. To their eyes humans look freakishly odd, but not offensively so; they smell awful, but fortunately S'sssksskss can close their nostrils and ignore it. They will always expect humans to learn their languages and customs just as easily, and will be mildly offended if they don't, but their languages are VERY difficult for humans, -2 to Linguist skill. One exception to this; anyone who has previously learned a language that uses tonal clicks etc. such as Bantu has no negative modifier.
S'sssksskss time ships are typically huge twin-hulled designs, almost floating cities. They discovered quantum theory before they invented the Displacer, and guessed from the outset that they were likely to change time-lines; accordingly each is a self-contained world, a city carrying everything needed to sustain a nomadic life or found a new civilisation.
Generate S'sssksskss on 28 points with the linguist skill free at MIND +1. Average characteristics are 4-5, with 6-7 high but still reasonably common. They have two natural attacks, Claws and Bite, both with the usual default damage etc., and may also know Martial Arts, Melee Weapon, etc. Due to their mental agility they have one odd attribute; extreme adaptability. In game terms they can move points from one skill to another that uses the same characteristic. For example, a S'sssksskss with Brawling 5 and Athlete 6, both based on BODY 4, could concentrate on a series of combat moves for several days while neglecting other athletic pursuits and end up with Brawling 6 and Athlete 5. They can't modify characteristics this way.