There are very few legends of the wererat, so what is known about them is very scarce and hard to come across. The general consensus however in the information that you can find on the wererat is that they are sneaky, reclusive creatures that are prone to stealing and thievery.
The human appearance of the wererat is said to be that of an unkempt human, often with long stringy hair. They are also said to often be skinny individuals with rather fast reflexes. In addition, it is also said that, like normal rats, they are most likely to be found in/around sewers.
In their rat appearance, the wererat is said to be almost indistinguishable from a normal rat aside from its size – it is said that in rat form wererats are very large!