This race, first conceived over two years ago, is still one of my personal favorites; I took some pages from the case-building caddisfly larvae common in the streams of the Pacific Northwest's more rural areas.
The trevata are a race of frail, humanoid insects. Though they posses indoskeletons, their predecessors also constructed exoskeletons, bonding surrounding materials (bark, rocks, etc.) to their skin by secreting a transparent paste. These shells served both as protection and camoflauge. As their civilized culture began to develop, they started to carefully construct their outfits and wear masks to establish their identity. Their progress was equivalent to 6th-century earth when interstellar contact was made. Now the majority of the Trevata spend much of their lives in customised suits of armor.
• Medium: As Medium creatures, trevata have no special bonuses or penalties due to their size.
• A trevata's base land speed is 30 feet.
• Easy Breathing (Ex): A trevata requires much less oxygen to breathe than a human does, and can hold its breath for a number of rounds equal to 10 x (Its constitution modifier) without having to make constitution checks. If exposed to a dangerous inhaled effect, a trevata gains a +5 species bonus on any required saving throw.
• Carapace: The trevata construct shells covering virtually all of their bodies by bonding materials to their hide with a transparent paste. Bonding or unbonding to a suit of armor or other shell takes 2d4 hours.
-- While not bonded to a suitable shell, a trevata suffers a -2 penalty to strength; they rely on their exoskeletons in order to fully exert themselves. Also, they suffer a -2 natural armor penalty to their defense and their massive damage threshold decreases by 3.
-- The Trevata can bond to any armor that they’re wearing, usually supplementing lighter armors with other articles of clothing. Once the bonding is complete, the armor gains the following bonuses: The maximum dexterity increases by 2, the armor class penalty decreases by 2 and the armor is treated one category lighter than normal for purposes of movement, proficiency and other limitations. Light armor doesn’t count as armor except in terms of available equipment slots; thus a trevata with no proficency in armor could bond to a light undercover vest and get the full bonus to defense. These bonuses last for as long as the armor remains bonded to its wearer.
-- The Trevata can also combine available materials (garbage, rocks, bark, thick clothing) to form a makeshift shell that grants a +1 armor bonus to AC. At the DM’s option, the materils used may serve as camoflauge, granting up to a +4 bonus on hide checks.
-- The same paste that bonds the armor to the trevata can repair damage by filling craks and holes, then hardening. Trevata who have seen much battle often have scars covering their armor that eerily resemble those found on living flesh. Damage to a bonded suit of armor is repaired at the rate of one point per character level per day.
• The trevata have unusually fast response times. They gain a +2 racial bonus to initiative checks and reflex saves.
• +2 racial bonus to survival checks: The trevata maintain a strong instinctual connection to the “outdoors,” even those who have dwelt in cities all their lives.