Uncle Jimbo's Bug Huntin' Range
Julie Czerneda's Species Imperative trilogy has some pretty interesting concepts for aliens.
Another designer has already started looking at Sinzi. Mygs, Grumnoii, Ar, staff and Trisulians (except in the very rare circumstances when heroes might encounter free-ranging males) are exotic but not in ways that require a lot of rules. Ehtzif are interesting but only appear briefly. It's probably not possible to discuss the Dhryn or Myrokynay without serious spoilers for the books.
A Frow shows slight resemblances to a spider, flounder or flying squirrel, with a full leg and membrane span somewhat larger than a human's height. On their homeworld they live on the walls of immense rift valleys.
Frow form hyper-stratified societies of which the currently dominant culture resembles a caricature of human armies of the 18th to 20th century. They wear elaborate hats and other adornments to denote their ranks. Frow are divided into three types roughly corresponding to genders, denoted by the pronoun/titles Se, Ne and Sene.
STR 6-13: Frow require physical fitness to survive their lifestyle, but are more lightly built than humans.
Free Broad Skills
Climber: On vertical surfaces that resemble rough stone in firmness and availability of footholds, a Frow can move at walk, run or sprint speed without making a check. On slightly unstable or difficult surfaces such as earth slopes or overhangs, a Frow must make an Athletics-climb check at a -4 bonus to move successfully. Se suffers the usual skill penalties for running or sprinting but never becomes stuck or falls. When climbing on flexible objects such as ropes or sheets, or very crumbly surfaces, a Frow's climb bonus is only -2.
Overbalance: A Frow attempting to perch on se's lowermost limbs and walk across a horizontal surface must make an Acrobatics-walk check each phase. Penalties apply for crumbly surfaces such as loose earth, gravel or debris. On a Critical Failure, the Frow falls down, suffers 1d4s damage and must make a Resolve-physical resolve check to get se's self upright. On a Failure, the Frow makes no progress that phase. On an Ordinary to Amazing success, the Frow moves 1, 2 or 3 metres. A Frow can also crawl along on se's back at half walk speed, but avoids doing so as it is horribly disorienting and undignified.
Slow Fall: If a Frow can slow se's descent using se's inter-limb membranes, the Frow counts falling distance as half as far, takes no damage from falls adjusted to Extremely Short, and cannot suffer worse than a Medium impact. This is not effective in vacuum or if the Frow's membranes are confined. Frow habitually fold their membranes around themselves when sleeping or as a gesture of rejection, social reserve or fright.
Militaristic: A Frow who does not have the Combat Spec profession or secondary profession may nevertheless purchase the broad skills Unarmed Attack, Modern Ranged Weapons, Security or Tactics at list price - 1. Some Frow are also good at Demolitions despite their instinctive aversion to such tactics.
Cliff Evaluation: A Frow gains a -1 bonus on Knowledge, Physical Science and Technical Science checks related to rock formations, walls or structures.