The stinkbird, which may be found in several different nations across South America, is the national bird of Guyana.
This colourful bird is widely derided for its pungent odour, clumsy, loud, and peculiar eating habits.
Herbivorous hoatzins get their distinctive odour through the fermentation of plant matter in the lower oesophagus and crop.
Regrettably, the breakdown of food in the foregut results in compounds that have a distinct dung-like odour.
These African giants don't stink all year long, but during mating season, their testosterone levels spike by as much as 60%.
Hormones released through their pores during this period are unpleasant to smell, and
the 80 gallons of concentrated pee that seeps through their skin every day further adds to the unpleasantness.
The muskrat is a semiaquatic rodent with a rat-like appearance and a strong, unpleasant odour.
These are animals that live in wetlands, and their rear feet are webbed for swimming while their front feet are tiny and used for digging.
The glands at the base of a muskrat's tail produce an unpleasant musky odour during mating season.