In this story Suske, Wiske, Lambik and Aunt Sidonia time travel to the 17th century where they work as musketeers for the French king.

They have to fight against a French duke, Le Handru, who used a super strong thawed caveman, Jerom, as his secret weapon.

Wiske discovers that Jerom also has a softer side when he plays with her doll, Schanulleke, and is scared that she will die because she refuses to eat.

This convinces Jerom that Wiske is nice and he is motivated to join their side instead, even travelling back to the 20th century with them, thus becoming the final main cast member of the series.

When other people around him act aggressive or showcase other heavy emotions Jerom always remains restrained and master of the situation.

In De Malle Mergpijp ("The Silly Marrowbone"; 1973) he even goes through an identity crisis and briefly returns to his prehistoric ways.

When making contact with electric utensils Jerom is able to produce energy[7] and when he drinks gasoline he can run at car speed.

Jerom is also known for his "T-slag" ("T-blow"), which is a type of strike where his opponent is hit, but only falls down knocked out a few seconds later because his brains only realized it then.

[14] When he is about to fight extremely violent he deliberately makes a huge dust cloud, asks the readers beforehand to close their eyes or lets the artists cover up the panels with a large curtain.

Halfway the plot he is often temporarily eliminated by poison, hypnosis, magic or a sleeping potion, only to make a triumphant return in the end.

He owes his enormous power to a shaman who drew a cave painting of a strong man, then, with aid of a marrow bone, blew a magical powder on the drawing to bring him to life.

[22] At a certain point Jerom was frozen in ice and only thawed in the 17th century by French duke Le Handru, who used him as a secret weapon.

Suske, Wiske, Lambik and Aunt Sidonia were able to make Jerom a "good" person and made him travel along with them to the 20th century.

[23] However, in De Nerveuze Nerviërs ("The Nervous Nervii"; 1967) professor Barabas makes the contradictory claim that Jerom descended from ancient Gauls.

The series could be described as a humoristic super hero comic in which Jerom wears a golden suit with cape and drives a flying motorcycle.

The production tempo was so high that a new Jerom story appeared every week, causing the quality to drop considerably.

In 2014 a new spin-off series was created around Jerom: J.ROM - Force of Gold, drawn by Dutch artist Romano Molenaar, best known for continuing Storm after Don Lawrence's death in 2002, and written by Bruno De Roover.

This spin-off is drawn more realistically in an American superhero comic style, inspired by the work of Frank Miller.

Jerom also appeared as "Big Billy Bigg" in a series of adventures in U.K comic "Sparky" between February 1968 and September 1969.

Vandersteen remembered that he received complaints from readers that "their breakfast no longer tasted well after seeing Jerom in the comics section".

In the Suske en Wiske musical "De Stralende Sterren" (1994) Dirk Bosschaert played the part of Jerom.

Jerom can also be seen as part of an illustrated wall dedicated to "Suske en Wiske" in the Laekenstraat in Brussels, Belgium.