They where created by Isse the Mad about 7000 years ago. He created them to be helpers in his laboratories and to do repairs in his great machines.
The fact that they where created by a mad archmage tend to make the weaseling feel alienated towards humans, their religions and believes.
They are not really humanoid weasels as the name suggests but rather a a mix between lemur and rat. They are usually about 4-5 feet tall.
They love fish, especially raw and yes, they sometimes smell quite bad.
Humans rarely consider the weaselings their equal and weaselings often live in poor conditions doing low class labor. Every now and then you do meet weaselings that have risen to influential positions like merchants or tavern keepers. Weaseling craftsmen usually have a very good reputation.
The maximum strength for a weaseling is 11 and the minimum dexterity is 15.
Weapon and Armor Restrictions
Like humans they do not have any weapon or armor restrictions.
Being small and nimble they receive a +2 to AC against huge humanoid creatures like giants or trolls.
Knack for mechanics
Isse the Mad somehow imbued the weaslings with a borne knack for everything mechanical. On 1-3 on a D6 they can disable a mechanical trap, open a mechanical lock or some similar mechanical task.
They receive +2 on saving throws vs. mechanic traps.
Optional Level Restriction
If you want a level restriction use the same as you would for a halfling in your game.