Klingon serpent worms. Gagh is usually served as fresh as possible, or "best served live". It is traditionally prepared and eaten by poisoning the worms and eating them in sauce while they are still alive. Gagh is killed in one's mouth and the blood is savored. If ingested while alive, it will act as a parasite inside the body. Some Klingons say that they don't care for the taste of gagh, but like it for the fight it puts up when eaten.

There are reportedly at least 51 varieties of gagh, each with a distinct flavor.