Answer: Trichuris trichiura adults
The photos in this case show most of the characteristic identifying features of adult T. trichiura (a.k.a. whipworms) including the classic "whip" shape and eggs with bipolar plugs. The full adult shown is a male as evidenced by his reproductive structures and curled tail. Note that the skinny end is the anterior aspect and not the tail like many students of parasitology would initially assume. The full body of the female is not shown, but you can see characteristic eggs coming out of the uterus.
The stichosome is clearly visible in some of the photos; this prominent glandular organ is seen in trichurids such as Trichuria and Trichinella (as well as some other nematodes) and consists of a row of multiple unicellular cells called stichocytes. The stichosomeruns along the posterior aspect of the esophagus and is a key identifying feature in both intact and sectioned worms. The stichosome opens into the esophageal lumen and has both secretory and absorptive functions.