Back to the Future’s Christopher Lloyd is confirmed to guest star on the December 1 episode of The Big Bang Theory, and every fan of TBBT, BTTF or both are pretty much excited.

However, no details are yet available about his role or the overall storyline of the episode, according to Variety.

Our beloved TBBT has been host to many Sci-Fi and Pop Culture figures over its ten-year run, and judging from the appearances of celebrities in the past, we have narrowed several possible roles Lloyd will play during the episode.

Christopher Lloyd As Himself Source: USA TodaySource: USA Today

Who can forget when James Earl Jones who voiced Darth Vader, and Carrie Fisher who played Princess Leia in the Star Wars original trilogy appeared on TBBT? The actors appeared on “The Convention Conundrum” Episode of Season 7.

Jones and Sheldon sort of went on a trip and ended up pranking Carrie Fisher on her house, who came out of her house holding a baseball bat.

Also, Wil Wheaton’s recurring role as himself is an important part of the characters’ stories. Elon Musk had also appeared as himself when he volunteered at the soup kitchen during “The Platonic Permutation.”

If Lloyd does appear as himself in the episode, it would be fun to see Sheldon and the gang fanboy over him. Just imagine their faces.

Christopher Lloyd As Doc Brown Source: Mentalfloss

The guys are proven fans of the Back to the Future franchise and including Emmet Lathrop “Doc” Brown in one of the character’s dreams sequences could be pretty amazing.

In the earlier seasons of the show, we have seen celebrities and other Sci-Fi creatures appear on dream sequences. Remember Battlestar Galactica’s Katee Sakhoff in “The Vengeance Formulation” and again on “The Hot Troll Deviation” episode with George Takei as Howard’s “projections.”

In “The Nerdvana Annihilation,” Sheldon and Howard were seen to have dream sequences while sitting on the time machine prop from the movie The Time Machine. In Sheldon’s dream sequence, he has entered April 28, 802701 in the time machine and was attacked by Morlocks.

Now, if his character becomes a vision in a dream, it would be very entertaining. It would also be cool if the show would approach the “dream” as a collective delusion so they can all interact with Doc Brown.

Plus, seeing Lloyd back in his Back to the Future costume will be priceless for all fans.

Christopher Lloyd As Someone Else

We’ve seen this done with Bob Newhart when he played Arthur Jeffries also known as Professor Proton, Sheldon’s childhood hero. If Lloyd is given an original role in the series, it would be a good idea to make his character have some similarities with Doc Brown. Perhaps someone who’s selling his pre-owned DeLorean car? You know, just in case someone in the group needs a new lift.

Or he could play an Uber driver with a DeLorean. This will be good, especially if it’s like this (I came up with this one, please don’t judge me. I know the show’s writers know better):

Sheldon: Hey, are you taking us to the future?

Driver: No.

Penny: Too bad. I would’ve had asked you to take us to the day I have my third Oscar.

Sheldon: Oh, Penny. Why would you date three people with the same name after you divorce Leonard?

(Cue audience cringing laughter.)

So, aside from that painful attempt at script writing there, what character would you want the great Christopher Lloyd to play in the episode? Share your thoughts.