The Streamrats were a group of rats who lived on the streams. Their Boss was named Girfang. When Girfang's son Riddig annoyed Martin the Warrior and his companions traveling downstream, he was hit in the tail by a slingstone. He then went crying back to his father. Martin and his friends fired slingstones at the Streamrats with such vigor that Girfang hit his son for lying, saying that it must have been at least a dozen otters. Riddig, in pain, said quickly that that was the true story, and the Streamrats left, not wanting to fight with a dozen (albeit imaginary) otters.
The Streamrats owned a few logboats with which they used to plunder. Their number is unsure, maybe around thirty.
The Streamrats appear in The Legend of Luke.