The actor, who's played some of filmdom's most beloved characters, including Doc Brown in "Back to the Future," Professor Plum in "Clue," and Uncle Fester in the "Addams Family" films, was born on October 22, 1938 in Stamford, Conn.
Partly because of his height, and partly because of his manic intensity and commitment to even the wildest characters, he's portrayed a series of eccentrics, from mad scientists to aliens; had an impressive, award-winning theater career; and will always be remembered as Reverend Jim on "Taxi."
In honor of his 75th birthday, we've come up with 75 reasons why he's so awesome.
1. He's played a Klingon, a cartoon, the Wizard of Oz, an angel, a leper, and a geriatric vampire.
2. He stands an impressive 6'1."
3. Because he's so tall, he had to hunch over to appear in the same frame with "Back to the Future" co-star Michael J. Fox, who is a mere 5' 4 1/2."
4. His films have made more than a billion dollars worldwide.
5. Lloyd's ancestors came over on the Mayflower.
6. The first movie he ever saw was "Hamlet," with Laurence Olivier, which his mother wasn't sure he'd get. She was wrong.
7. His nickname in the theater was "The Fog," as a friend put it: "He doesn't talk much but he's a real good guy."
8. Although he is a sitcom legend, he is NOT the same Christopher Lloyd who's an executive producer of ABC's "Modern Family." (Although he sometimes doesn't correct fans who tell him how much they love the show.)
9. The October 17 Facebook post claiming he had died got more than a million likes. Fortunately, it was just a hoax. (http://en.mediamass.net/people/christopher-lloyd/deathhoax.html) Fake rumors of his death have actually circulated for years.
10. He said he got into acting because "there was going to be nothing else I was competent doing."
11. His first Actors' Equity performance was in a 1961 production of "A Midsummer Night's Dream" in Connecticut, with Bert Lahr ("The Wizard of Oz"). He was billed as "various attendants."
12. He won an Obie Award and a Drama Desk Award for his first New York acting gig, the title role in Peter Handke's "Kaspar," in 1973, which is based on the true story of a 16-year-old boy who was kept in a small container his whole life and never socialized.
13. Lloyd is so notoriously shy that he never does talk shows, but he did appear on "Taxi" buddy Tony Danza's talk show in 2004.
14. Lloyd played Banquo in a 1974 production of "Macbeth" at the New York Shakespeare Festival, with Carol Kane, Christopher Walken, and Peter Weller. Who has a time machine?
15. In a 1977 production of "Happy End" with Meryl Streep, he went on despite almost literally breaking a leg the day before the play's opening. He ripped two ligaments in his right leg and had to wear a cast from hip to ankle.
16. To prepare for his first major screen role in "One Flew Over the Cuckoo's Nest," he lived in a mental institution and studied the patients for a few weeks. He stayed in character the whole time, even when not on screen.
17. It had taken so long for him to get a film role that, on "Cuckoo's Nest," he kept expecting the director to tap him on the shoulder and say, "This isn't working out."
18. He nearly turned down "Back to the Future" to star as Hans Christian Andersen on stage.
19. A producer had him in mind for Doc Brown because of his role as the equally bizarre John Bigbooté in "The Adventures of Buckaroo Banzai Across the 8th Dimension."
20. Did Doc steal the flux capacitor from Buckaraoo Banzai's rocket car? The "overthruster" sure looks similar.
21. He based his performance as Doc Brown on Albert Einstein and conductor Leopold Stokowski.
22. He got Doc Brown's pronunciation of gigawatts as "jigowatts" from a physicist who consulted on the film.
23. He has reprised his role as Doc Brown several times, including in a music video, where he drives the DeLorean to a nightclub and takes over the DJ booth.
24. He played the good, time-traveling doc again in a Nike short film that raised money for Michael J. Fox's Foundation for Parkinson's research.
25. He starred in quite possibly the greatest "Amazing Stories" episode ever, "Go to The Head Of The Class," as a terrifying teacher.
26. He won two Emmys for his role as Reverend Jim on "Taxi."
27. He wore his own clothing -- a jean jacket, raggedy jeans, and tennis shoes -- to the "Taxi" audition for Reverend Jim and instantly got the part.
28. He based Reverend Jim's facial expressions on those of his half-brother, who was 22 years older than him. "I sent him a photo of me in character thanking him. I don't know that he was really happy about it," Lloyd said.
29. He played Sherlock Holmes opposite his older brother, Sam, who was Moriarty, in a 1990 play.
30. His nephew is Sam Lloyd, who played Ted Buckland on "Scrubs."
31. He learned to play the bongos for "The Oogieloves in The Big Balloon Adventure."
32. He appeared (along with "Clue" cast members Lesley Anne Warren and Martin Mull ) in the "Clue"-centric episode of "Psych."
33. Since his career, as he put it, "has had a dearth of romantic roles," he loved "Back to the Future III" because he got to kiss Mary Steenburgen, whom he said he "kinda had a crush on."
34. He regrets he didn't get to do his own stunts, like jumping aboard the train, in "Back To the Future III."
35. He described being able to play Uncle Fester, one of his favorite characters as a boy, as "a real kick in the ass."
36. He has appeared in over 200 plays and more than 150 TV episodes and movies.
37. He has a "F*ck Yeah" Tumblr blog dedicated to him.
38. He once turned down Martin Scorsese: "Martin has a habit of using the same actors over and over again," he joked "So that was probably a bad career move."
39. He got choked up at NYCC last year when saying, "As hard as times are, I'm still hopeful for the future."
40. He said his favorite part of making "Star Trek III" was wrestling with the giant worm. Oh, and that guy Shatner.
41. He joked last year, "The longer I live, the less competition I have [for roles]."
42. He doesn't just give autographs, but he does give great photo ops.
43. He inspired this tattoo.
44. His immortal line, "I was frozen today!" in "Suburban Commando" has, of course, inspired an internet meme.
45. He is the subject of this awesome Onion article, claiming that Bowling Green State University is "just going to start claiming him as an alumnus."
46. A match made in mad scientist heaven: Christopher Lloyd guest starred as Walter Bishop's rock idol on "Fringe."
47. This summer, he appeared "for peanuts at a tiny not-for-profit theater in the East Village" in "The Caucasian Chalk Circle."
48. When asked what he thought of Justin Bieber starring in a remake of "Back To the Future," he simply said, "I don't see that at all."
49. Leonard Nimoy wanted Edward James Olmos to play villain Kruge in "Star Trek III." However, he finally agreed with a producer that Lloyd was more "operatic" and physically intimidating.
50. Long before he portrayed a Klingon, Lloyd (as Reverend Jim on "Taxi") complained that while he loved "Star Trek," he didn't like the Klingon leader because the writers had him say things a "real Klingon just wouldn't say."
51. He appeared, uncredited, as "Mr. Fishladder" in the pilot of the short-lived live-action series "The Tick."
52. He played himself, along with most of the surviving "Taxi" cast, in the movie about Andy Kaufman, "Man on the Moon."
53. He appeared in two of the biggest flops in film history, "Baby Geniuses" and "The Oogieloves in the Big Balloon Adventure." Then again, "Clue" was considered a flop, but has since become a cult favorite.
54. In an apparent ode to two of his most popular films ("Clue" and "Who Framed Roger Rabbit"), he played a character named "Professor Toone" in the TV series "I Dream."
55. His leprous, finger-losing character in "Things To Do In Denver When You're Dead," is called (hilariously) "Pieces."
56. After losing his home in Montecito to a devastating fire in 2008, he said that he no longer had to worry about organizing his movie memorabilia.
57. He got raves from the NY Times for his performance as pompous Pozzo in a 1998 production of the classic absurdist play, "Waiting For Godot."
58. Although he had doubts about taking on the iconic role of Willy Loman, reviews of his 2010 run in "Death of a Salesman" said he was "magnificent" and "haunting."
59. Lloyd's maternal grandfather was one of the founders of the Texaco oil company. (Is that why we see a Texaco station in both time periods in "Back to the Future?")
60. He has admitted he will rewatch "Back to the Future" when it's on TV.
61. The scene in which he hangs from the hands of a giant clock in "Back to the Future" is an homage to silent film star Harold Lloyd (no relation).
62. Whenever Judge Doom isn't wearing glasses in "Who Framed Roger Rabbit," he never blinks.
63. Bruno Kirby offered him his fat suit from "The Godfather: Part II" to play Uncle Fester.
64. He has said that his shocked reaction in a classic episode of "Taxi," in which a chair moves after he lays his late father's suit on it, was a complete accident.
65. The role of Reverend Jim started out as a one-shot guest appearance.
66. In the '70s, he traveled around Greece for six months by horse and cart.
67. He has cycled up the coast from San Diego to Seattle, and along the coast of Nova Scotia.
68. Roger Ebert praised Lloyd's Independent Spirit Award-winning performance in the movie "Twenty Bucks," saying, "Sometimes an actor will walk into a movie for 15 minutes or so, and show you such strength that you look at him altogether differently... I was so absorbed, I'd basically forgotten about the 20 bucks and the rest of the movie."
69. Fans started a Facebook campaign for him to host "Saturday Night Live."
70. He told Moviefone last year how much fun he had playing "Star Trek" villain Kruge: "It was a relief to be free of all those human traits. I could go out there and be a bastard!"
71. His death scene in "Star Trek III" is considered one of the best in the franchise.
72. Among his many cast reunions: He guest starred on "Spin City" with Michael J. Fox and "Numb3rs" with Judd Hirsch.
73. In "Back to the Future II," the restaurant shows sitcoms, including Fox's "Family Ties" and Lloyd's "Taxi."
74. He told Parade he never wants to retire. "I'm itchy for my next job."
75. The date on the 2015 USA Today newspaper in "Back to the Future II" is October 22nd, Lloyd's birthday. In 2015, he will be 77.