(n.) One who describes animals, their forms and habits.

anatomist animal physiologist anthropologist bacteriologist biochemist biometrist biophysicist botanist conchologist cytologist ecologist entomologist ethologist geneticist helminthologist herpetologist ichthyologist malacologist mammalogist natural scientist naturalist ophiologist ornithologist physiologist protozoologist taxidermist zoo-ecologist zoographer zoologist zoonomist zoopathologist zoophysicist zootaxonomist