Currently touring the United Kingdom is I Was A Rat!, a stage play based on the book by British author Philip Pullman.
Pullman's 1999 book opens with elderly couple Bob and Joan answering a knock at their door, and finding a boy in a tattered page's uniform. When asked who he is, the boy can only tell them, "I was a rat". Having no children of their own, Bob and Joan take the boy in and name him Roger. They soon find he has distinctly ratty behaviour - he cannot eat with a spoon and, on his first night, chews his bed linen to shreds.
Bob and Joan attempt to find Roger's parents, but find the authorities disinterested and unhelpful. After Roger runs away during an examination by the Philosopher Royal, he gets exploited as a sideshow freak, used as an assistant to house-breaking, and eventually takes refuge in the sewers. With the local newspaper The Scourge feeding the hysteria, he is eventually caught and, as "the monster of the sewers", put on trial for his life.
I recently attended a performance at the Liverpool Playhouse. The stage play follows the book fairly faithfully; it was extremely well done, and I had so much fun watching it that I returned to catch it a second time before the production moved on to their next venue.