Tapeworm-Taenea saginata
The beef tapeworm Taenea saginata can be up to 12 feet in length (see picture on the right) once it reaches adult stage. Here’s how this works: A cow or pig eats vegetation infected with the egg or proglottids (a piece of the tapeworm). One of the immature stages of the tapeworm embeds and migrates through the tissues of the animal. A human comes along and eats the undercooked or raw meat and the immature parasite matures in the intestinal tract of the human.