Dog

Canis lupus familiaris, also known as dogs are a common species of domesticated animal found on Earth most often as the companions of humans as it was humanity that domesticated them.

Appearances and Closely Resembling Species

 * Dogs of unknown origin often appear in Star Wars, as well many non-canine but highly canine-looking creatures share the name "dog" because of several closely resembling qualities.
 * Akk Dogs are an alien species originating on Haruun Kal.
 * Cyborrean Battle Dogs are cyborg hounds.
 * Frog-Dogs are a reptilian alien species with a few resembling features with dogs. Used as 'slave pets' and/or assassins and spies
 * The character of Chewbacca (and the Wookiee species by extension) was partially inspired by George Lucas' dog Indiana.
 * In the DC universe there are many dog-like creatures from various worlds:
 * Kryptonian Dogs are visually identical to Earth dogs in most ways, and possess the same abilities as the humanoid Kryptonians under the yellow sun.
 * G'Nort's species, the G'newtians, resemble humanoid dogs.
 * An episode of Teen Titans features a sapient, green-skinned, shape-shifting alien dog which belongs to the dim-witted alien Soto.
 * Pemalites are a highly advanced dog-like species in Animorphs. Their Android servants, the Chee, created the domestic Earth dog by fusing the last of the Pemalite DNA with the Earthly wolf.
 * Calots, a species from Mars; highly resembling dogs; and with most Martian species using them like dogs; as companions and/or guards.
 * In the comedy film Good Boy!, Earth dogs are depicted as an alien race from the Sirius System which sent agents to Earth to subjugate humanity several millennia ago. They have failed miserably, as they became pets instead.
 * Marvin the Martian's pet K-9 is a Martian dog: seemingly identical to the Earth variety except for its green skin and enhanced intelligence (they appear to be semi-sapient at least, and sometimes are depicted as sapient and even capable of speech).
 * The Remoolians from Men In Black can easily pass as a Pug dog. Even beneath their disguises their real appearance is still very similar to a Pug.
 * The Doctor Who universe is populated by numerous canine races, including the Lycanthropes, Killorans, Hroth, Galks, Poodles and Barcelonan Dogs. Also, the robotic K9 units invented by Prof. Marius are modeled like mechanical dogs and display similar behavior (such as wagging tails).
 * The Hounds of Tindalos are extra-dimensional, vaguely dog-like entities from the Cthulhu Mythos which dwell in a different temporal realm.
 * The Wanshang Dhole from The X-Files is a kind of wild dog capable of shape-shifting and its bite can turn a Human into another Dhole; similar to a Werewolf or the Manitou (a distinct species from another episode).
 * A Xenomorph born from a canine host is called a Runner, and distinguished from the Human-born variety by its quadruped stance and lack of dorsal spines.
 * The Hell-hounds are a species used by the Yautja which bear a passing resemblance to Earth hounds, and serve similar purposes.