John D. Rockerduck is a cartoon character created in 1961 by The Walt Disney Company for the Duck universe.

This trait makes him a natural antagonist to Scrooge, who is capable of going towards absurd lengths to spare even trivial sums of money.

Their rivalry is further contrasted by the fact that Rockerduck was born into luxury, rather than earning his fortune by his own hard work, which is another reason for Scrooge's, and sometimes even Glomgold's disrespect toward him.

In contrast to the Scottish birth of Scrooge, Rockerduck claims to be hailing from England like his father Howard, where he is sometimes depicted to be living, and shown to be the more active in Europe than in America, with some stories having Scrooge having to buy land from him or compete with him to be able to expand his businesses on the European markets.

This is often ignored in other stories to be able to have the rivals meet on a daily basis as in the case of Scrooge's other rival, Flintheart Glomgold (who in the Barks stories lives in South Africa) with John primarily managing his activities from a large business building he owns in Duckburg, and the three characters sitting at the same table in the Billionaires' Club of the city.

Many of the stories presenting him, especially during the 1970s and the 1980s, compare and contrast his and Scrooge's methods of organizing their business in order to gain profit.

Sometimes Rockerduck's plans against Scrooge involve more severe actions like abduction, hijacking his planes, or blackmailing him.

Such stories emphasize Scrooge's morally ambiguous role in Italian Disney comics, where he frequently exploits Donald, or makes his life miserable in other ways.

When cooperating with Rockerduck, Scrooge may be particularly insufferable, and the reader is invited to sympathize with Donald as the underdog in his conflict with the ruthless and powerful billionaires.

(1995), written by Rudy Salvagnini and drawn by Giorgio Cavazzano, Scrooge is convinced to take a holiday on "Earth-D" by his counterpart "Scrooge-B".

The alternate Rockerduck has no visible businesses save for a greengrocery which he manages, and says that he made a mistake investing in the failing McDuck stock.

Rockerduck admits that although odd to be part of McDuck's recovering business empire, he also say "it makes me feel almost like the free-spending tycoon I used to be!"

While John's father was a shrewd businessman but a mild-mannered man, his mother was a rather snobbish woman who spoiled her son.

Despite John's protestations, Howard started having a friendly discussion with the inexperienced prospector and ended up teaching Scrooge the secrets of the job, and helping him earn ten thousand dollars.

While Scrooge had to leave for Scotland to attend to family business, John again protested against his father's relationship with the "filthy peasant".

Howard, to whom Scrooge resembled his younger-self, introduced his son to corporal punishment in an effort to teach him some manners.

Although some depict John as a distant cousin of Scrooge, through an unspecified genealogical connection, others have traced their rivalry to their ancestors.

Arguably, the most notable among the later stories is an eight-part saga named Storia e gloria della dinastia dei paperi ("History and glory of the Duck dynasty") by Guido Martina, Romano Scarpa, Giorgio Cavazzano and Giovan Battista Carpi, first published April 5-May 24, 1970.

by Lars Jensen and Maximino Tortajada Aguilar, Rockerduck (as well as Flintheart Glomgold) was made bankrupt by Donald Duck, after the latter had inherited Scrooge's fortune and turned it into a charity company.

However, the end of the story reveals that it actually takes place in an alternate future, caused by Scrooge travelling 100 years into the past to retrieve his #1 dime.

Howard Rockerduck was born poor, but worked his way to the top and became a very wealthy man, and was helped by a "lucky strike" when he prospected for gold.

Shortly after, Rockerduck got so scared by the behaviour of a Scottish woman (actually Magica De Spell in disguise) that he went home to the USA.

Magica's interference would also indirectly result in the conception of John D. Rockerduck, as Howard gave up on Scottish girls and instead focused his attention towards England in the hopes of finding a bride, to which he would ultimately be successful.

Later, he helped Scrooge make a juridical claim to the Anaconda Copper Mine, which were owned by Marcus Daly and some rich investors.

Rockerduck, voiced by John Hodgman, made his animated debut in 2019, in the DuckTales reboot, being a recurring antagonist in the series.

Prior to his appearance, Rockerduck was described by series co-creator Francisco Angones as a robber baron and billionaire competitor of Scrooge McDuck during the 1930s.

While in the United States the character has long been obscure, in many countries Rockerduck is almost as well known as Scrooge himself, to the point that his name has been used as a metaphor example.