Still, he's never quite gone this far. This month's I, Frankenstein sees him take on Mary Shelley's creature in a modern-day spin on a character that, in four years time, will be celebrating his 200th birthday.
"He's a good character," says Eckhart, when we meet in London. "He's a character that everybody can relate to because he's created, he's rejected by his father and called an aberration and an abortion. He's cast out, he has to find his own way in the world. He's ostracised by society, he's looking for love and his purpose in life. All the thematics are there for everybody. I'm like 'This is my teenage years!' Who isn't looking for love and their purpose in life?"
While it's hard to believe that the lantern-jawed Eckhart ever suffered in his teenage years, his point about the universality of a character created in a lab and brought to life by electricity is well-made. After zombies and vampires have dominated cinemas, it was only a matter of time that Frankenstein staggered back onto our screens. It can't have hurt that Danny Boyle's 2011 National Theatre stage production, starring Benedict Cumberbatch and Jonny Lee Miller, drew rave reviews.
The way Eckhart sees it, the creature has been ill-served by the classic Universal monster movies of the past. "If you look at the monster in Mary Shelley's Frankenstein, he's very articulate, he's kind, he's light-footed, but yet somehow in the cinema, he's become this lumbering cumbersome monster. He's inarticulate. Well, he's very smart. Mary Shelley did not make him a dummy. He learns very quickly. He's sensitive. He has feelings. His feelings get hurt. That's what I looked at."
While I, Frankenstein comes from a Darkstorm graphic novel by Kevin Grevioux, Eckhart went back to re-read the 1818-published Mary Shelley novel - which he'd last encountered in school. What struck him was the isolation the creature feels. "Imagine the anger in a lonely moment, when he wants to be out or he wants to be accepted. Imagine the anger and the resentment - that's what I was looking for in the movie."
Quite what Shelley might make of her character in the hands of Eckhart and writer-director Stuart Beattie (who helped script the Pirates of the Caribbean movies) is anyone's guess. After a prologue set two centuries back, when Eckhart's creature kills the sweetheart of his creator, Dr Frankenstein, the film flashes forward to the present-day. Living a life in the shadows, the creature - he has scars, but no bolts - suddenly finds himself in the midst of a war between gargoyles and demons.
Eckhart, 45, makes no attempt to disguise the fact that I, Frankenstein is aimed at the younger market - from the heavy use of computer effects to the fact that the monster learns the art of kali stick fighting. "I know that some people because it's a literary, historical character will [be negative]. But you would get that if you did anybody."
Certainly, Shelley's story, itself borrowed from the myth of Prometheus, holds a spell over actors. This month sees the DVD release of the 2004 TV mini-series Frankenstein, which co-starred the likes of William Hurt and Donald Sutherland (and, as the creature, the slightly less impressive former Bros pop-star Luke Goss). Admittedly, fashioning it as a Gothic love story, with the creature more hunky than horrific, wasn't quite the way to go.
In the past couple of years, numerous Frankenstein projects have been in the works - including an adaptation of Peter Ackroyd's novel The Casebook of Victor Frankenstein and Wake The Dead, a modern-day take on the myth based on the 2004 comic series that was set to be produced by Guns N' Roses guitarist Slash. The company behind the Twilight series were also said to be developing Kenneth Oppel's novel This Dark Endeavor: The Apprenticeship of Victor Frankenstein.
First to be bolted together, however, is Scottish director Paul McGuigan's Frankenstein, starring Daniel Radcliffe, James McAvoy and Downton Abbey's Jessica Brown Findlay. Written by Max Landis, the son of American Werewolf In London director John, "It's such a mad script," says Radcliffe. "It's madder than you'd expect coming out of a studio. I know it sound like a contradiction in terms to say that it's original when it's Frankenstein, but it is. It's a completely original take on it."
With McAvoy cast as Victor Frankenstein, Radcliffe is playing his assistant Igor. "It's about two young men at the forefront of technology, one of whom is bursting with ambition and the other who has to temper that ambition with morality - and that's Igor." With the hunchbacked assistant "given a backstory" for the first time, Radcliffe reports that on the front of the script, it reads: "based on the American pop culture zeitgeist interpretation of Mary Shelley's Frankenstein."
Collating interpretations of the character, from the Boris Karloff years to Mel Brooks' Young Frankenstein, seems intriguing - though whether it will have the same impact as the Twilight films did for vampires is uncertain. As far as I, Frankenstein goes, Eckhart is brave enough to predict it will. "I think that the character is so archetypal and so iconic that it will resonate with people all over the world. I've talked to people in Asia, Russia, Europe and America - and they're excited. There's a market for this."
Frankenstein is released on DVD on January 18. I, Frankenstein opens on January 29.