Skunk Kusai is a thief and mob leader who frequently clashes with Astro. He is sleazy, confident, and eager for money and power. Skunk appears in almost every Astro Boy series, and throughout Osamu Tezuka's works.
Osamu Tezuka originally modeled Skunk Kusai's design after the American actor Richard Widmark, particularly Widmark's character Tommy Udo in the 1947 film Kiss of Death. This led to Skunk's exaggerated character design of a long forehead and sunken eyes. In later art, Skunk is coloured to have blue skin to make him look ethereal and sickly.
He is a lanky, strong, and odd-looking man in his 30s-40s who sometimes appears with blue skin. He is blonde, usually appearing with short hair and bangs, or a chin-length bob cut.
Skunk initially appears in the episode "Zero the Invisible Robot", where he is bailed out of prison and rejoins his gang. He then abducts the robot Zero and begins to use him for criminal activity.
In the English dub, he is renamed "Fearless" Fred Fink. While he does appear as a secondary villain in several other episodes, only this episode appears in the English dub lineup.
Skunk initially appears in the 1980 series as an associate of Count Walpur Guiss. He builds their idea for the Omega Factor device and pitches it to Dr. Tenma. When turned down, Skunk and Guiss steal a copy of Astro's robot body blueprints and build the child version of Atlas. This endeavor goes horribly wrong, as Atlas rebels after Skunk mistreats him and Guiss kills Livian. Leaving Guiss for dead, Skunk flees to the city.
Skunk is reunited with Atlas only briefly, when Atlas comes across Skunk and his sidekick Pilat fleeing the police. Skunk attempts to use Atlas as a crime tool, which backfires once more.
Skunk appears throughout the 1980 series as Astro's regular adversary, each time with a larger gang of men. He is responsible for rigging a race, hijacking a robotic Frankenstein's monster, and stealing a laser-pointed robot head from a black market auction, among other heists. In the 1985 Canadian dub, Skunk is renamed as "Slippery", and his voice actor there is unknown.
Skunk first appears in the episode "Into Thin Air", where he steals the robot Denkou to use them for covert robberies. He at first seems to be raising them as a paternal figure, but easily abandons Denkou after they become hunted by the police. He has a much smaller gang in the 2003 series, assisted only by Jazz, a paunchy mechanic, and Blues, a tall computer hacker. The three of them are known for kidnapping a scientist and using her shape-shifting robot to rob safes, and for hijacking the giant robot Jumbo to break Skunk out of jail.
- Skunk appears briefly in the 2001 film Metropolis, as a general and advisor to Mayor Boon.
- He is also a reoccurring enemy in the manga Atom: The Beginning, much younger and a high-ranking member of a robot-using criminal organization.
- Skunk appears in one episode of the 1993 Ambassador Magma OVA. He appears as a nameless humanoid alien who stalks the main character, Mamoru. Skunk corners Mamoru, begins to transform into his alien form, but is shot in the chest and killed by a robot boy named Gam.