While Rachel Weisz was able to pull it off in the first two Mummy films, the third saw her replaced by Maria Bello, who seemed to lack the charm that made the chemistry between the two main characters so realistic.
Replacing an actor or actress with someone else is fairly standard practice, but it might have been better to write the character out entirely this time. Instead, have poor Evelyn fall victim to a curse, and introduce a new leading lady to break Rick out of his funk.
Joel Grey as Chiun in Remo Williams: The Adventure Begins
Joel Grey was cast as a Korean martial arts instructor in this film, but there was one obvious problem with that — Joey Grey isn't Korean. He's American. The man had to go through four and a half hours of makeup every day to look like an elderly Korean man.
The producer Larry Spiegel assumed they would be able to find an actual Korean who could do the work, but they ended up having a lot of trouble and cast Grey instead. Even at the time, the casting was highly controversial.
Jared Leto as Morbius in Morbius
Yeah, there are a lot of terrible things about this movie. The only good thing that came out of it was the memes, and even those are fading. Jared Leto thinks he's a great method actor, but as "Suicide Squad" proved, that doesn't mean he is one.
The big issue might be that Leto cares too much – he was using crutches to get around while filming part of Morbius, and thus he needed help going to the bathroom. On the other hand, it might just be that the Leto experiment needs to end.
Mark Wahlberg as Elliot Moore in The Happening
"The Happening" was destined to be a flop once people figured out what was going on, but Mark Wahlberg's performance as main character Elliot turned it into almost a farce. Trying to paint Wahlberg as a science teacher just trying to stay ahead of death simply didn't work.
He had a stupidly confused look on his face for the film's full run time, and a lot of the delivery he gave was so bad it became memorable. It's not the kind of role he usually takes, and it showed. But, of course, it's possible no actor would have done well with that material.
Marlon Wayans as Calvin in Little Man
Incredibly, taking the face of a full-grown actor and superimposing it over the face of a nine-year-old actor with dwarfism didn't work out. Who could have known? We can't tell if it's offensive or just plain bad, but one critic described the film as "possessed by the devil."
Wayans seems to think the movie is fun, but few others agree. The film earned itself a triplicate of Golden Raspberry Awards, and you can bet your bottom dollar that one of those went to Marlon Wayans. There were so many effects it was like Star Wars, but Even Jake Lloyd could do better than this film.