You're looking for a man named Hyde. Hyde?!
Russell Crowe. Why get another actor for Hyde when you have a perfectly fine and versatile performer in Crowe who can play intimidating so easily?
COOKIES AND MILK!-Ed
It depends on their vision of Mr. Hyde character.
If they go strictly by-the-book route, then Hyde must be played by a different actor than that of Jekyll, since the original novella describes them looking completely different (even their body build is not the same - Jekyll is a tall man, while Hyde is very short).
I don't see them getting another actor besides Crowe, I anticipate Hyde being monstrous with CGI or make up enhancements put on Crowe.
COOKIES AND MILK!-Ed
I hope they don't make Hyde a big monster.
If I'm not wrong, he was first portrayed as such in The League of Extraordinary Gentlemen comic book, which was then transfered into the movie adaptation, and that design was later carried over to the film Van Helsing (2004).
It seems they did that ONLY to have a figure similar to the Hulk, since The League is essentially a superhero comic/film.
However, in a non-superhero film, there is no need of making Hyde look like the Hulk.
Furthermore, I would really, really like to see a book-faitful Hyde, because he was described as [I'm paraphrasing]: ''A person so revolting to look at, so vile and disgusting... and yet, without any physical deformities on his face and body.''
So, it seems that book-Hyde simply looks and feels evil, but doesn't look monster-like.
In fact, here's my suggestion for Hyde - Brad Dourif.
His Grima Wormtongue from The Lord of the Rings films is how I pictured Mr. Hyde.
http://images2.fanpop.com/images/answers/3000/3515_1237758572508_400_300.jpg
Hasn't Crowe already been confirmed for Hyde?
Anyway, I always wanted to see Paul Bettany in the role, if it were up to me.
If they do go for two actors- someone please cast Paul Bettany?!?! He & Crowe were magnificent together in MASTER & COMMANDER: THE FAR SIDE OF THE WORLD, so it would be great to see them back on screen together again. If not, then please cast Paul Giamatti (I'm sure I mispelled that, sorry) in some supporting role to Crowe, as the two were great in CINDERELLA MAN.
"There is still hope." - Arwen
Why are Dr. Jekyll/Mr. Hyde even in a mummy movie in the first place?
"I like simple pleasures like butter in my ass and lollipops in my mouth." - Floyd Gondolli
HI they are going to remake all the original monster movies
Mummy
Frankenstein
Dracula
Creature Black Lagoon
Wolman
and link them afterwards so will have a monster club type film as with marvel universe
So Hyde is in mummy and all the others as per original comics in 1940s and they fight other creatures so to speak but also kill humans so both sides of the coin
should be good if done right
Guy Pearce
shareMy pick: Brad Dourif.
His Grima Wormtongue from The Lord of the Rings films is very close to the original book version of Mr. Hyde:
http://images2.fanpop.com/images/answers/3000/3515_1237758572508_400_300.jpg
(short, evil-looking, disgusting, but with no visible physical deformities)