Cecil Fredricks

Cecil Fredricks is the main antagonist in Night at the Museum. He is also one of the three former night guards that used to work at the Museum of Natural History before Larry. He is potrayed by Dick Van Dyke. 

Night at the Museum
By the time of the first movie Cecil is over 80 years old and had served in a library and then a museum. In the first movie he is an elderly night security guard about to retire from the American Museum of Natural History. He hiresLarry despite his unpromising résumé. Because of recent financial troubles, the museum plans to replace Cecil and his two colleagues Gus and Reginald with one guard. They advise Larry to leave some of the lights on and warn him not to let anything in...or out. Once night comes, Larry discovers that the exhibits come to life, which Cecil did not tell him since Larry won't believe him at first. Cecil gave Larry an advice to study history to prepare himself better. The next night, Larry uses what he has learned to better control the exhibits. However, things go awry, and one of the exhibits went outside when sunset came and has turned into dust. Dr. McPhee almost fires Larry in the morning, but gives him one more night.

Larry brings Nick to the museum to show him the exhibits, but none is alive. They investigate and catch Cecil, Gus, and Reginald in the act of stealing the tablet and other valuable objects. Like the exhibits, the guards receive enhanced vitality from the artifact; wishing to retain their health and fund their retirements, the three plan to frame Larry for the thefts, and disabled the tablet to stop the exhibits from interfering. Nick reactivates the tablet, but Cecil locks him and his father in the Egyptian room and flees with the tablet. Larry releases the Akhmenrah's mummy from his sarcophagus. The pharaoh speaks English from many years as an exhibit at Cambridge, and helps Larry and Nick escape. The three find the other exhibits fighting all over the lobby, and Larry convinces them to work together. Although some of the exhibits capture Gus and Reginald without difficulty, Cecil escapes by stagecoach with Larry, Nick, Akmenrah, Jedediah, Octavius, and Attila the Hun in pursuit in Central Park, where they stop him and regain the tablet. At the end of the movie, Cecil, Gus, and Reginald are forced to become museum janitors to evade being sent to jail.

Night at the Museum: Battle of the Smithsonian
Cecil, along with his colleagues didn't return in the sequel, however they did appear in the alternate ending included on the DVD and Blu-ray releases.

Night at the Museum: Secret of the Tomb
In Egypt 1938, he was a participant in an archeological expedition where they were trying to find the Tablet of Ahkmenrah. Cecil discovered the tomb of Ahkmenrah's family accidentally when he plunged into a hidden pit that was later revealed to be the tomb entrance. His interests in the tablet begin here.

Cecil and his cohorts return in the third film, were they reside in a retirement home. He appears to have reformed as he immediately tells Larry he has no interest in the tablet anymore and enjoys his time at the home. Cecil also helps Larry find answers when the tablet's magic is disappearing. Cecil tells him to take it up with Ahkmenrah's dad, Merenkahrie, who, along with his wife, resides in the British Museum of Natural History. Cecil's past is revealed as he is the cause for the founding of Ahkmenrah and his parents while on an expedition with his dad in his minor age. Also it is revealed that, despite his age, he is quite a skilled dancer.