I feel like I haven’t been giving the cast their comedic due on these character studies, so I’ll take this time to gush a bit. As far as the movie goes, Martin Mull’s performance of Col. Mustard is probably the funniest in the film. I know, that is a very tall order when the rest of the cast has such greats as Tim Curry, Madeline Kahn, and Christopher Lloyd all jockeying for position.
I think what makes his depiction of Col. Mustard so funny is how almost all of his interactions with the other characters make comedy gold. His verbal sparring with Wadsworth is some of my favorite comedy scenes in any movie:
[Col. Mustard] Are you trying to make me look stupid in front of the other guests?! [Wadsworth] You don't need any help from me, sir-- [Col. Mustard] --THAT'S right.
And his accusatory back and forth with Madeline Kahn let her show off the colorful aspects of what could easily have been a very one-dimensional character in Mrs. White.
All that aside, I like the Colonel mostly because his character remains interesting and stays a viable murder suspect throughout the film, all the way through to the ending(s). He is a bit out of place and seems overwhelmed at times, but he always has an air of being capable and in control of himself (the polar opposite of Mr. Green).
What makes him endearing to me is that we can clearly see his military experience evident in his evaluations of the situations he finds himself in, his ability to come up with plans, in gathering information, and taking a leadership role when the situation warrants it.
That last one is really key for me. Whenever he takes ‘command’ of the situation, it’s only when things get out of Wadsworth’s control. It’s more an advisory role, never bossy or overbearing: Something that’s a bit of a cliché when depicting anyone in the military in murder/mystery films and plays. It is a lazy acting choice that Mull thankfully avoids.
With the praise to the acting out of the way, let’s address the character himself.
Interestingly, while doing this write-up just now it occurred to me that Col. Mustard, like Mr. Green & Ms. Scarlet, doesn’t reveal the real reason for his blackmail (being a war profiteer) during that scene in the study.
We have it hinted at with Wadsworth mentioning that he drives “a very expensive car for someone who lives on a Colonel’s pay”, but after the comical explanation he gives of coming into money after he “lost his mommy and daddy” is enough to leave the reason given (that he patrons Ms. Scarlet’s brothel) as sufficient to be blackmailed over.
This is a bit different from Ms. Scarlet and Mr. Green in that we find out the real reason for Col. Mustard being blackmailed before any of the separate endings, which means it’s canon no matter which ending you pick, whereas Green and Scarlet’s real reason for being blackmailed need only be true if you picked their specific endings as canon.
But there’s ONE THING I don’t understand with the one murder he is given credit for in the final ending:
That darned secret passage.
Once again, everything lines up perfectly with motive, opportunity, and most of the means to knock off the motorist. But even if Col. Mustard recognised the motorist, put it together that he was the one who told the blackmailer about the war profiteering, decided to murder him, switched the keys, separated from Ms. Scarlet, and got the wrench – he’d still need to know that there was a secret passage into the lounge in order to use it.
I stretched a bit with Mrs. Peacock being told about the secret passage by the cook (assuming she knew), and it is canon that Yvette knew of them. So, we could go 2 routes: either that Col. Mustard was also familiar with the house as Mrs. Peacock might’ve been, or that Yvette herself might’ve told him.
Being a war profiteer with enough wealth to afford expensive cars, it’s conceivable that he might also try to hob-nob with the rich and powerful in the same social circles as Mrs. Peacock. He’s also the first to arrive at the house, indicating he might’ve been there before.
On the other hand, if Yvette was his preferred call girl, there’s no telling what they might’ve talked about. If we take it as canon that Scarlet’s real business was espionage, and there’s no reason it couldn’t be given any ending of the movie, perhaps establishing rapport with a Colonel at the Pentagon would involve local gossip about old mansions with secret passageways and such.
And if that’s too much of a stretch, remember that Col. Mustard and Yvette have some alone time right after he arrives. Probably a good segue into talking about the secret passages would be the fact that the library doors hilariously close behind him to the false facade of more books, making the library door a ‘secret passage’ in and of itself.
And there we have Col. Mustard: a compromised Colonel who will probably rise higher in the ranks at the pentagon, after all is said and done.