Linguatula serrata is a species of cosmopolitan zoonotic parasite, belonging to the tongueworm order Pentastomida.

The adult parasite is dorsoventrally flattened, tapering backwards resembling a vertebrate tongue, thus, inspiring the common name of "tongueworm".

When eaten by a definitive host, infective nymphs either attach in the upper digestive tract or quickly travel there from the stomach, reaching the nasopharynx.

More generally, linguatulosis can be considered a form of "pentastomiasis", which refers to all diseases caused by pentastomids, including porocephaliasis.

Among Linguatula serrata infecting Cairo street dogs, 10% were juveniles, 59% were males, and 31% were females, corresponding to a sex ratio of 1.9:1.