Ok I accidentally thought a little too hard about the Ssstram and now I have an OC species for animorphs I guess??
I can't really draw so you're gonna have to vibe with my word picture here: the Ssstram are a snake like species with a long, thin body. On one end they have a mouth, two large movement-focused eyes, and nostrils, all of which are used primarily for hunting and eating. (The yeerks enter their body through the nostril)
On the other end of their body their tail breaks into several long 'fingers' which are very sensitive to temperature and texture and also covered in smaller eyes which see mostly color and detail and are less focused on movement.
The Ssstram had recently discovered steam power and the uses of electricity before the yeerks got them. They had not yet invented flight or space travel.
Ax's comment in book 8 about the hork bajir having a biological time clock that sent them to war every 62 years was actually him misremembering a fact about the Ssstram. Although that's not the only detail he misunderstood. When a Ssstram reaches approximately 62 years old (measured in Ssstram years, not Earth years) they undergo a hormonal change that increases their aggression for a short period.
While this period is very significant in the majority of Ssstram cultures with lots of rituals surrounding it (in many Ssstram cultures the number of spouses you were allowed to have was dependent on how you performed during battles with other 62 year olds), 62 year old Ssstram were often used in war/conflict between Ssstram groups
The yeerks of course do not care about this or any other aspect of Ssstram culture, most view the heightened aggression period of the Ssstram as "annoyingly Taxxon like"













