All of the different characters of Whoville are anthropomorphic creatures with qualities that appear somewhat human and somewhat dog-inspired. In "How the Grinch Stole Christmas," the seminal book by Dr. Seuss, the Whos of Whoville have bodies with two arms, two legs, eyes, hair and ears that resemble human beings. Their mouth and nose, however, look like they belong to a dog.
Dr. Seuss first introduced his Whoville characters in the book "Horton Hears a Who," which was released in 1954. The two books feature Whos that look fairly dissimilar to each other, outside of general characteristics. Even the major motion pictures based on the original books show different representations of the characters.
The Whos in the "Horton Hears a Who" book are furry from head to toe. Even their hands and feet are covered in fur. The movie shows a different iteration of the characters, in which their faces and appendages are smooth, but they have lots of head hair and wear furry clothing that closely matches their own hair color.
The movie version of "How the Grinch Stole Christmas" depicts the Who characters as slightly more human. The characters have human skin tones and pointy noses with no philtrum.