Basic Trope: Aliens clearly based on a terrestrial animal
Straight: The Denya are large anthropomorphic pig people, who have extravagant mud bath facilities, spend large amounts of time looking for rare mushrooms and eat their meals out of a trough.
Exaggerated: The aliens are called the Pigs, and look and act exactly like normal pigs other than being sapient and capable of speech.
Downplayed: The Denya are Kemonomimi with pig snouts, ears and tail.
Justified: The Denya are directly related to a species of pig found on Earth.
Inverted: An alien planet's non-sapient species resemble humans.
Subverted: Human astronauts going to another planet describe its inhabitants as being like pigs. When we actually get to the planet and see the aliens, it turns out they don't look like pigs, the astronauts were just being metaphorical.
Double Subverted: ...They actually look like Tyrannosaurus rex.
Parodied: The Pig People are at war with the Wolf People, The Pigs have to keep building increasingly strong fortresses that the Wolves won't Huff and Puff away!