Hound by the pound
Yes, it's true ? Koreans eat dog. While theoretically illegal, in practice the law is not enforced and dog meat soup (보신탕 bosintang or 영양탕 yeongyangtang) remains a popular dish among those looking to improve male virility or just beat the summer heat. It is not popular among most younger Korean people or women though. Another option is suyuk (수육), which is just meat boiled with spices to eliminate smell and make the meat tender.
Aside from the cultural taboo, there are some issues regarding how the dogs are raised, butchered, and processed. These days, dogs are generally not beaten to death to improve the taste, but calling the conditions in which dogs are raised and butchered humane would also be an exaggeration. Even in Korea, where many people are pet owners, people get quite opinionated on this matter. So take anything you hear with a grain of salt.
In any case, you're unlikely to end up chewing on Snoopy by accident, as dog is only served by speciality restaurants, and as they rarely advertise you will have to actively seek them out. If you do make the effort, a bowl can go for under W10,000 and you'll find that dog tastes broadly like beef or veal, if perhaps a tad gamier.