Fosdick was rail-thin, with slicked-back black hair, a thin parted moustache, and a pronounced under-bite that ended in a pointed jaw even more pronounced than Tracy's.
Fosdick is a slightly dim-witted though doggedly determined police officer. Starting as a patrolman in 1923 and becoming a detective in 1948, Fosdick lived on a meager salary of $22 per month. Fosdick was frequently fired and re-hired, at which point his pay rate would be re-set to the apprentice wage of $11 per month. Fosdick would not have been able to afford to eat if not for the meals provided to him by his long-time fiancée, Prudence Pimpleton.
The fictional Fosdick was the hero and role model of Abner Yokum, and it was Fosdick's marriage to Prudence that prompted Abner's marriage to Daisy Mae (not the result of a Sadie Hawkins Day race, as many believe). This was due to Abner's membership in the Fearless Fosdick Fan Club, which required him to do anything that Fosdick did. Fosdick's wedding was later revealed to be a dream, but Abner's marriage was legitimate.
In the world of Li'l Abner, Fosdick's creator was a cartoonist named Lester Gooch, a parody of Chester Gould. Gooch was often depicted as certifiably insane, reveling in the gore and mayhem he was drawing.
In June of 2016, Dick Tracy experienced a dream in which he found himself paired with Fosdick to capture Evil Eye Fleegle, another character from Li'l Abner.
- Max Allan Collins provided the introduction to a collection of Fearless Fosdick strips.
- Al Capp was publicly complimentary of Dick Tracy and Chester Gould.
- When asked by Vera Alldid, Dick Tracy cited Fearless Fosdick as his favorite comic strip. As a result, Alldid developed the habit of addressing Tracy as "Fosdick". This was also the inspiration for Alldid's new comic strip J. Straightedge Trustworthy, apparently.
- Fosdick was the spokesman/mascot of Wildroot Cream Oil, a real-world hair treatment.
- In the 1950s, Fosdick was adapted into a children's TV puppet show. Fosdick's appearance and personality were presented in a while that closely resembled the comic strip, but other elements of the strip (such as the extreme violence and Fosdick's large chinned fiancée) were omitted.
- A continual gag in the strip is the excessive amount of collateral damage that Fosdick commits in his pursuit of criminals, taking the violence in Dick Tracy to a humorous (if often gruesome) extreme. Fosdick himself was frequently shot, stabbed, poisoned, or otherwise assaulted in the line of duty, and he would often display with pride the various "Swiss cheese"-style holes that covered his body.
- In one notable Fosdick case, Fosdick killed more then 600 citizens to prevent them from eating a can of poisoned beans.
- As a parody of Dick Tracy, Fosdick has a sharp chin and a black suit, as well as a fedora hat similar to Tracy (although he also often wears a bowler). While Tracy is usually clean shaven, Fosdick has a small mustache.
- Fosdick appeared in a Gasoline Alley storyline in which Walt Wallet attends a gathering at the Cartoon Retirement Home. A pearl brooch belonging to Maggie Jiggs (from the strip Bringing Up Father) goes missing, and Fosdick arrests Wallet (who is soon proven innocent).
- Dick Tracy's encounter with Fosdick has been reprinted in the comic book Dick Tracy Meets The Spirit.