This is mostly a summary with some notes on stats and mechanics thrown in. Page numbers are Mongoose Core Rules. I might do the other races later, but I loved Dralasites so here goes.
For people who did not play Star Frontiers: Dralasites are basically your shape-changing rubber-glob aliens. They love jokes, especially human ones, and long baths with perfumes and aphrodisiacs which they absorb through their skins. They can not imitate others by their shape-chaning abilities, they can just deform themselves.
You can find out more in the "Alpha Dawn" PDF, see: http://starfrontiersman.com/downloads/remastered (I am not sure how legal those PDFs are, the website states they have "limited permission" to distribute, whatever that means.)
Dralasites:
Genderless
Sees only in B&W
Most important sense is smell
-> None of these have game effects in the way of stats/rules, but should be kept in mind in "perception check" situations
Slow Metabolism (page 42), lower movement rate (4m/round; page 60)
Notable Strength (+2) (Page 42)
Notable Endurance (+2) (Page 42)
Weak Int (-1) (page 42)
Dralasites also have Lie Detection 5%, and +10% on empathy. I am not sure how best to handle this in MgT (I am new to it, remember); Looking at the skill list and based on what Mr31337 said, I'd probably give them a +1DM on Investigation, Persuasion and Diplomacy on any situation dealing with detecting the intent of the other party, detecting lies, and general appeals - anything that works on the emotions of the other, but not, for example when rolling on how to conduct a formal dinner etc.
Alternatively, especially in a psionics heavy campaign, you could consider this a PSI power (Telempathy, page 153) but I'd recommend against this for a "normal" game.
Elasticity
- Can grow (DEX score-2, min 1, max 10) number of limbs. Takes 5min, one at a time. Limb can be 1m long, no less than 10cm thick. "Fingers" can be up to 10cm long, no less than 1cm thick. Must designate one limb as "dominant", similar to how humans are left/right handed.
- Can absorb and regrow "broken" (disabled) limbs - does not cure damage but means they have a full set of functional limbs again (I think the only place where penalties for missing limbs are described is page 37).
- Must spend 5 min to form an air pocket in its body before entering water, otherwise will not float naturally. Can swim either way, but will sink if it stops moving without that air pocket.
- Can not do more things at the same time than humans, no matter how many limbs he has (a limit of the brain's ability to multitask), but could for example hold on to a rope with one limb while working on something else with two others.
(Note that the Star Frontiers rules are inconsistent on that later point, I am not sure how much that would break MgT balance so I'd probably limit their number of attacks etc.)