The purple pentapus is a small, five-legged invertebrate that leaves red polka-dot marks when its tentacles are detached from a person's skin. The creature is difficult to remove with brute force once attached, but if one strokes its head, a gesture which the pentapus immensely appreciates, it will readily release its grip.
Team Avatar encountered this species in the city of Omashu while navigating through a sewer pipe. When Sokka crawled out of the sewer pipe, he had several pentapuses clinging to his face. Upon removal, several spots were left over, and the team used it as an excuse for breaking curfew, under the name of 'pentapox', a fictional disease. The distinctive suction marks left by these animals were later used as a way to lead the citizens of Omashu outside the captured city's gates, as the marks fooled the guards into believing the inhabitants were infected with pentapox.
The purple pentapus is a five-eyed, five-tentacled, octopus-like creature that lives in the sewers of Omashu and is roughly the size of a human fist. Using the small suction cups on its tentacles, it latches onto targets, though it is apparently harmless. These tentacles are used to grip the sides of sewers in order to eat algae and other food.
The purple pentapus resembles an octopus but on a much smaller scale. Unlike the octopus, which has eight arms and two eyes, the small invertebrate has five arms, like a starfish, and five eyes.
- The purple pentapus' name is the strongest example of alliteration in both series, as it repeats the "p" sound four times. Other creatures in the series whose names are alliterations include the canyon crawler, fire ferret, flying fishopotamus, goat gorilla, pygmy puma, snail sloth, and spider snake.
- Penta (πέντε) is a Greek numerical prefix for "five", and pus is derived from the Greek pous (πούς), which means "leg". The name thus refers to the five limbs of the animal, much like how the octopus' name comes from it having eight limbs.
- In the video game Avatar: The Last Airbender – The Burning Earth, the pluralization of "pentapus" was noted to be the Latin "pentapii", versus the more conventional English pluralization of "pentapuses".
- Ehasz, Elizabeth Welch (writer) & Spaulding, Ethan (director). (April 7, 2006). "Return to Omashu". Avatar: The Last Airbender. Season 2. Episode 3. Nickelodeon.
- From older Avatar: The Last Airbender official site, originally on Nick.com. Encyclopedia now broken, archived at The Lost Lore of Avatar Aang - Creature: Purple Pentapus.
- Walkthrough for Avatar: The Last Airbender – The Burning Earth - 6:17 (video). Retrieved on October 29, 2012.