Taran is headstrong, adventurous, good-hearted, cheerful and courageous, though occasionally foolhardy, and harbors an intense desire to prove his worth and heroism through noble acts. Indeed, much of the movie centers on Taran's search for his own worth. Taran was a foundling discovered by Dallben, the enchanter, and farmer. As Taran grew up, he became restless and longed for adventures beyond the borders of Caer Dallben. His time would eventually come when, just after being granted the position of Assistant Pig-Keeper for Hen Wen, Dallben's oracular pig, the animal escapes her enclosure.
Taran valued his own life and he initially refused to sacrifice himself, even to negate the necromancy of the Black Cauldron. However, after seeing what it was capable of, he nobly prepared to jump inside from a distance, despite Eilowny's pleas, preparing to commit suicide for the greater good, which goes to show his adventures with his friends have heightened his bravery even further. He even tried to make the sacrifice when Gurgi, who had caused him a lot of grief, wanted to do it for him, begging him to reconsider his current course, which also shows he is forgiving.
Taran is a slender, 13-year-old boy with brown hair, hazel brown eyes, and fair skin. He wears a green vest over a yellow long-sleeve shirt, green pants, and brown boots.
Taran follows Hen Wen and soon finds himself caught up in an epic struggle that will determine the fate of the land of Prydain. During his adventures, he meets (and eventually falls in love with) the beautiful Princess Eilonwy. With her help, he frees the ancient, magical sword Dyrnwyn from King Rhitta's tomb, an event that will set in motion the war that could bring about the defeat of the Horned King. Taran is assisted in his quest by many friends, including the self-styled Bard Fflewddur Fflam, the shaggy creature Gurgi, and the stalwart dwarf warrior Doli.
Finally, the three are captured along with the newly acquired Black Cauldron which the Horned King used to summon the Army of the Dead. He sends them to destroy all opposition. Fortunately, Gurgi arrives, rescues his friends, and flings himself into the Cauldron to negate its necromancy ability (though Taran himself nearly does the latter). The Horned King returns to the room where the ritual was performed and finds Taran who he believes the Cauldron's failure was his doing. He grabs the boy and lifts him off his feet, but Taran pushes the Horned King into the pull of the Cauldron. The Horned King grabs Taran again and tries to throw him into the Black Cauldron, but the cauldron pulls the Horned King in instead and rips him apart. His castle soon follows; Taran and the company barely escape. After the Witches of Morva arrive to retrieve the cauldron, they plan to give the magic sword back to Taran. But Taran, who finally realized Gurgi's true friendship, decides to permanently give up the sword and chooses to trade the Cauldron for the revival of Gurgi instead. After that, Taran, Eilonwy, Fflam, and the latter return home under the watchful eyes of Dallben and Hen Wen.
A portrait of Taran appeared in the Tokyo Disneyland attraction Cinderella Castle Mystery Tour in the entry room of the walkthrough attraction. It switched to a picture of the Horned King when the Magic Mirror enters the scene and begins to establish that a hero is nothing without their villainous counterpart.
Taran appears with Gurgi in a Sardi's style portrait in Shanghai Disneyland's Mickey & Pals Market Café to represent the film as part of the gallery's effort to incorporate every Disney Animated Features Canon film made up to its opening.
Also during the release of The Black Cauldron, Taran and Eilonwy were walk-around characters at the parks.
- Taran is the first human Disney protagonist to have red hair and green eyes. Quasimodo from The Hunchback of Notre Dame is the second.
- Taran and Eilonwy are occasionally featured in Disney merchandise. This is most likely due to Disney's general tendency to disassociate itself from their movie due to its darker tones, despite the cult following it gained on home video releases.
- In the early development stages of the film, Taran's age varied between 12, 15, and 20. Finally, the animators settled for Taran's age to be 14.
- Despite being voiced entirely by one actor, Taran's voice changes without any in-story explanation, possibly due to his voice actor Grant Bardsley going through puberty.
- Much of Taran's personality is similar to Luke Skywalker, in that in the beginning of their adventures, they wanted something more in their life, search for their calling in life and wanted to prove themselves.
- At one point, Gurgi calls Taran a great Prince. This is a reference to Bambi.