Outcast noun – One who is cast out or rejected by society. Rat and outcast are semantically related. In some cases you can use "Rat" instead a noun "Outcast".
Rat noun – A person who provides information about another's wrongdoing. Outcast and rat are semantically related. Sometimes you can use "Outcast" instead a noun "Rat".
Four children, from the most different backgrounds possible (a kind and caring noble-girl, a frumpy and snarky merchant daughter, an outcast trader girl and an egotistical street rat) become best friends and foster siblings, whose minds become mentally linked.
During Swartt Sixclaw's failed attempt at taking over Redwall in Outcast of Redwall, a rat captain named Scraw gets shot full of arrows after Swartt's archers mistook him for woodlanders hiding in the bushes.