Springing from the Belgian comic character Cubitus and originally named Dommel in Japan, Wowser is a large anthropomorphic white dog whose good-natured laziness is rivaled only by his enormous appetite. This insatiable hunger frequently propels him into trouble, disrupting his preferred routines of eating and sleeping with neighborhood antics or his owner's experiments.

He shares his home with the eccentric inventor Professor Ron (Professor Dinghy in some dubs), serving as the regular—and often unintended—test subject for the Professor's creations. These trials typically result in comedic mishaps caused by malfunctioning devices or sabotage. Wowser's days are further complicated by his recurring dynamic with the neighborhood cat, Ratso Catso (Blackie), whose annoying pranks frequently ruin his plans, though their relationship occasionally reveals flickers of friendship.

Wowser harbors a noticeable crush on the human character Linda Lovely (Cherry), reacting with visible heart-shaped eyes to her affection. He also contends with the often-rude neighbor Beatrice. Despite his generally easygoing nature, he displays distinct frustration when provoked, particularly by Ratso's mischief or Beatrice's condescension.

Physically resembling a polar bear more than a typical dog, Wowser possesses humanlike hands and feet, enabling him to walk upright and manipulate objects. His cartoonish design includes an exposed bellybutton. A running gag positions him as the primary comedic victim, enduring frequent slapstick injuries played for humor.

International adaptations reflect localization choices in his name: "Wowser" in English references his verbal tic of exclaiming "wow," while other versions use names like Cubitus (French), Ka'abool (Arabic), or Teodoro (Italian). No significant character development or background story beyond this core description appears across the series, movies, or spin-offs.