"The **Cymothoa exigua**, also known as the ""tongue-eating louse,"" is a remarkable and unsettling parasite that targets fish. It enters the fish’s mouth or gills and attaches itself to the fish's tongue, where it begins to feed on the blood supply, causing the tongue to atrophy and eventually fall off. Once the tongue is gone, the parasite anchors itself to the remaining stub and effectively *becomes* the fish's new tongue, serving the same function in the fish's mouth. The parasite continues