With 2014's X-Men: Days of Future Past, actor James McAvoy will get to show a whole new side of mutant leader Professor Charles Xavier. "The personal pleasure for me in First Class was presenting a Charles Xavier to the fans, but also a new audience, who's very different from the Charles that you expected," McAvoy recently told Red Carpet News TV. The actor went on to specify that the next time we see Chuck on the big screen, he won't be the same randy graduate we saw in X-Men: First Class. "The Charles in this film is unrecognizable from the Charles in the last film as well unrecognizable from the Charles played by Patrick Stewart," McAvoy said.

That makes sense considering the mutant mentor's habit of changing up his persona every few years in the comics – and after 50 years in the Marvel Universe, Professor X has gone through a number of transformations. Here are five versions of Charles Xavier, pieces of which might just make their way into Bryan Singer's upcoming mutant movie.

The Inappropriate/Intense Taskmaster

When Professor X debuted in 1963's X-Men #1, he was presented as a supporting character to the original X-Men – teenagers clearly intended to draw in the hip, young readership that Marvel was cultivating. Because of his teacher role, Xavier rarely got to be anything other than the team's drill instructor, putting them up against seemingly unstoppable tasks. He wasn't above manipulation, either, as he hired a shape-shifter to take his place for months, and he didn't step forward to clear the air when the shape-shifter was killed while impersonating him. In addition to being a bit too intense for high school kids, Stan Lee started – and then abruptly forgot about – a subplot wherein Professor X had the hots for the decidedly underage Jean Grey. It's probably best for 1960s Professor X to stay hidden in the back issue bins.

The Big Softie

Charles Xavier had to loosen up after recruiting a group of older and more capable X-Men in the mid-'70s. With heroes like Wolverine, Storm and Nightcrawler needing a less-stern hand, Xavier started to behave more like a peer. Sure, he tried some of his old teaching tricks with teens like Kitty Pryde and the New Mutants, but he actually listened to reason when they called him out. During this time period he even fell in love with Lilandra, the empress of the alien Shi'ar Empire. Fans got to see the human side of Xavier as he grew closer to Lilandra and struggled to use his new legs (which he got from a cloned body, because comics) to walk again. Yes, this is the Charles Xavier that went rollerblading with Jubilee. Patrick Stewart brought shades of this interpretation to life with every one-liner he's thrown Wolverine's way.

The Onslaught

However nasty he'd been to his pupils in the past, nothing compared to the time Professor Xavier's dark side gained sentience and threatened to tear the world apart. Prior to this incident, Xavier slowly grew callous toward his students, harshly criticizing the maturity and capabilities of longtime allies like Cannonball and Cyclops. Xavier was eventually separated from the Onslaught entity, but the formerly happy-go-lucky Prof hit a new low as he turned himself over to the authorities and took the blame for the immense damage caused by Onslaught. We've yet to see Xavier go evil on the big screen, and if the X-Men are going up against Apocalypse next in 2016, it might be years before we get a shot at seeing Xavier's bad side.

The World-Traveler

Xavier stepped back from the mentor role following a brief return to the X-Men in the early '00s. Instead, he focused his energy on traveling the world, righting the wrongs he felt he had ignored for too long. This Charles Xavier was more proactive and adventure seeking than past ones. He helped Genosha rebuild following a devastating Sentinel attack and later turned his attention toward helping his old student Rogue master her uncontrollable mutant power. During this time, Professor Xavier let other mutants like Cyclops and Emma Frost fill the mentor role as the mutant race struggled to survive. While McAvoy's Xavier acted as a mentor in First Class, he possessed a lot of Xavier's field capability and energy.

The Martyr

Currently, Professor X is causing a lot of drama for being a dead man. During the final act of last year's Avengers vs. X-Men event, Xavier's prized pupil Cyclops, who was under the influence of the cosmic Phoenix Force, killed him. His death polarized the X-Men even further and had ramifications throughout the entire mutant community, and Cyclops and those who follow him are now considered wanted fugitives. But because of his death, his dream of mutant and human peace now has a team of Avengers fighting for it – something that never happened while he was alive. Until news breaks that McAvoy or Stewart are definitely coming back for more psychic action following Days of Future Past, it's entirely possible that this Xavier will be the next one we see on film.