Monster's Escape from Another World

The life of an ordinary person is very trivial, but if an opportunity to become a monster is placed in front of you, are you willing to turn into a monster and roar around the world to pursue the freedom you long for? This is the story of the monster, this is his legend. PS: I'm not good at writing introductions, so please focus on books. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.