"Tu manges une tortue ?"
The official form of the question should be "manges-tu une tortue ?". Yet, in oral, subject and verb are generally switched. It could be question or an exclamation: "tu manges une tortue !". If a question, you would raise your voice on the word "tortue" and if an exclamation, your tone of voice would express surprise or reproof or anger... your choice.
To comfort you, it is illegal in France as well.