Dodongadon is a one-eyed alligator monster roughly human-sized, featuring two mouths: a small frontal one and a larger alligator-style mouth on the back of its head. It exhibits a childlike, naive personality.

First appearing in the manga chapters "Penguin Village S.O.S.: Part 1" and "Part 2," Dodongadon terrorizes Penguin Village, overwhelming the local Police Force. Arale Norimaki then playfully overpowers it. Dodongadon's defeat occurs when Kintaman falls from the sky, landing headfirst on it. Later, in "Penguin Village Dom-Dom-Dom!", Dodongadon appears passively among a crowd following Arale and Gatchan.

The 1993 reboot film *Dr. Slump and Arale-chan: N-cha! Penguin Village is Swelling Then Fair* reimagines Dodongadon as a supporting antagonist. Easily defeated by Arale and Gatchan, Dodongadon summons its mother, Mamangadon, to destroy Penguin Village. Dodongadon rides on Mamangadon's tail during her rampage. Following Mamangadon's defeat, both monsters reform. Dodongadon enrolls as a student at Penguin Village Middle School under Miss Midori Yamabuki. It makes a minor appearance in the sequel film *N-cha! Love Comes From Penguin Village*, where Arale informs it about Senbei's guest appearance.

Dodongadon possesses combat abilities, launching missiles from its rear mouth and exhibiting complete immunity to bullets and missiles. Mamangadon is its supportive parent. Adversaries include Rat (whose house it destroys), the Penguin Village Police Force, Arale, Gatchan, Kintaman, Kinoko (who insults it), and Suppaman (whom it easily defeats in the reboot film). Following reformation, Midori Yamabuki becomes its mentor.

Trivia notes similarities between Dodongadon's name and creatures from *Ultraman* (1966) and *The Legend of Zelda* franchise. Its head design resembles the Xenomorph from the *Alien* series and Frieza’s third form in the *Dragon Ball* series.