The Hawfax are a six legged arboreal species with a stiff covering closer to feathers than hair, large, forward facing eyes, a prehensile tail, and four toothed tongues in an otherwise jawless mouth. They are about suited for life in the trees as a human is suited for life on the ground: most wild animals can outperform them. They have remarkably strong grips. The entire creature is the length of a man's arm, not including the prehensile tail, and they weigh 40-60 lbs.
They naturally have longer lifespans than humans, but not by much: aging landmarks are at x1.5 of human numbers. Hawfax are a variety of dull colors by nature, but they wear clothes (their high internal temperature makes even the Amazon chilly) in all sorts of gaudy shades, often with patterns and prints. They don't grey with age, but they do wrinkle and get a weathered look. Males and Females are distinguished by smell, not by appearance -- something most humans can't pick up. Hawfax are largely serial monogamists. A pouch on both species is used to carry first their eggs and then their young, who are fed by regurgitation until they can digest their own food. Sticking things other than young in the pouch is considered disgusting, much like keeping items in any body orifice. Both Parents ideally take care of young, but this may or may not happen. Young Hawfax physically mature at about age 18, but in modern Hawfax culture don't really act like adults until they hit 28 or so.
Their senses are remarkably human. They have good color vision, a solid sense of hearing, communicate by sound, and have the delicate touch needed for any tool using creature. Their sense of smell is much better than a humans', but they don't see well in the dark at all.They see different colors than humans, and the two species have a very different appreciation of paintings. Art that doesn't rely on color translates fairly well though.
The BiologyThey are a mostly vegetarian species. Like all vegetarians, they can technically digest meat, but they don't recognize a corpse as food, and eating another animal is barbaric and repulsive to them. Killing an animal is just fine, provided it was a pest of some sort (which includes predators and rival herbivores), or a bug sized animals (though they are still picky about those).
Hawfax agriculture is based on trees. They brought a myriad of tree and tree dwelling vegetable species brought from their homeworld, but have found some of the local trees do as well or better in the local environment. Within the frame work of trees and vegetarianism, they are quite creative with their diet. Crops include bark, fruit, leaves, small bugs, (flowers?), seeds, shoots and flowers. They transform land into farms just as dramatically as humans, the result just is based on scaffolding and trees rather than floors and grass
Their biology is as earth-like as could be expected. Their biochemistry is similar if weird. They use a slightly different set of amino acids and their nucleic acid is entirely different but a lot of the same molecules play a lot of the same roles. Creatures from the two planets can eat each other (mostly) safely, and bacteria and parasites can theoretically jump between the two, but viruses cannot.
The CultureThe hawfax pride themselves on individualism, scientific progress, rationality, and ethics. They like to weigh issues in prolonged debate about if an action is fair to all concerned, including animals or criminals. They have a strong negative reaction to religion, a high value on personal freedom, and a keen interest in other cultures and creatures. These qualities are actually self selected: the colony selected individuals with these sorts of traits when it left the Hawfax home-world, which is far less homogeneous in its beliefs and values.
A GM running Hawfax right should find his players identifying with Hawfax more frequently than with their fore-bearers of the early 1900s, who today would be labeled as racist and imperialist. This is by design: hawfax have a fairly modern culture. They are not perfect or straw men though, just closer to modern culture.
Building CharactersTemplate 
-3 ST [-30], Move -2 [-10], Terrain Adaptation (branches) , Discriminatory Smell , High TL 3 , Wealth (comfortable) , Six Legs , Semi upright [-5], Night Blindness [-10], Feature: Non-Terrestrial Biochemistry . Feature: temperature range 60 to 115 (+25 F) .
Other considerations:Common Disadvantages: While not listed on the template, hawfax culture usually leaves them with appropriate disadvantages .. much as human culture does. Be aware of the gap and pick appropriate disadvantages accordingly. The broad minded quirk is extremely common though.
Quirk: Gets Cold Easily. A campaign that takes place in the wilds of earth that are not tropical rain-forest will find the hawfax constantly struggling against the cold, and this quirk reflects that. This should not be taken in campaigns in the wilds of the amazon, or that spend the majority of its time indoors, as the temperature tolerances will rarely come up.
Perk: Long Life. Most campaigns will not span enough time for a hawfax's long life to have any game effect. If they do last this long, hawfax should take this perk.
ST costs: In low combat campaigns, ST is often overpriced -- a disadvantage that is never used is not a disadvantage. GM's could at least consider dropping the cost of ST to 5/level, which gives the template a cost of . But in combat heavy campaigns the lower ST may be quite a disadvantage.
Building Humans:Non Iconographic (colors only -50%, Mitigator-20%) [-3] By nature, humans cannot perceive most of the color used on hawfax digital displays or even common pigments, which gives a penalty (usually -2 to -4) to using much of their technology. This can be overcome using special technology, but its rare. This should only be bought on humans who have increased their TL to that of the Hawfax.
Am I primative or are you advanced? The template given is based on human society as the default. If hawfax are the reference society, give humans Struggling Wealth [-10] and low TL 3 [-15]. This drops the cost of a Hawfax to [-25].