It's strange to see a Tarasque here as it is not a very well known or used monster outside of D&D. Unless the author is really into French folklore. In D&D, the Tarasque is the toughest monster that you could conceivably bump into outside of epic levels. It has a challenge rating of 30. To put that into perspective, an ancient red dragon (think Smaug from the Hobbit, but bigger + magic + no weak point) has a challenge rating of 24. The Tarasque is "The most dreaded monster native to the Prime Material plane.", a nigh unstoppable killing machine, an apocalypse given form. Given that the author probably took inspiration from the D&D version, it's kinda weird that our MC here just kinda found one. And is now going to... fight it? I dunno, seems odd.