Looking at the Greatest Villains in Monk History

Since 2002, viewers have revered Tony Shalhoub's Adrian Monk as one of the most iconic leading men in television history. In fact, without its memorable title character, we'd have to wonder if Monk would have had a more truncated run than the eight-season arc the show enjoyed for nearly a decade.

But as any savvy TV viewer will tell you, your protagonist is only as good as the antagonist. And luckily for Adrian Monk, he had many!

As the Peacock premiere of Mr. Monk's Last Case: A Monk Movie on December 8 draws closer, we at USA Insider thought about giving Monk fans some quality Monk history. Today, we're looking at the greatest villains in Monk ever crossed paths with, narrowing it down to five of the most devious. From main characters that loomed over the show's overarching storylines to one-off villains that made an impact on all of us (for nefarious reasons, of course), the show has had plenty of memorable antagonists over the years who consistently threw Monk-ey wrenches at our favorite leading man (sorry, we couldn't resist).

Here are our picks for the greatest villains in Monk's history.

With a villainous streak eclipsed only by his weight, Dale the Whale was a constant thorn in the side of Monk – and those he loved – for the duration of the series. 

We honestly don't know which of The Whale's sins were the most egregious. Some fans believe it's Biederbeck ruining the lives of Trudy and Monk in the years before her death, going as far as suing Trudy into oblivion for disparaging remarks she made about him in the media. This led to Monk memorably stating, "She only had thirty-five years, and he stole one of them."

Other fans point to the storyline that occurred later in the series' run that saw Dale the Whale, while behind bars, attempting to frame Monk for a murder he didn't commit. 

In the end, Dale Biederbeck got what he deserved – a lifetime behind bars living in relative squalor – but it still doesn't mean he didn't inflict immeasurable emotional destruction on Monk's life. To us, that's a hallmark of a great villain. 

Talk about despicable: Frank Nunn, as fans of the show know all too well, was the man responsible for detonating the car bomb that killed Trudy. Known as the "Six-Fingered Man" for well, obvious reasons, it was revealed Ethan Rickover hired him to assassinate Trudy Monk.

One of the most tense scenes in Monk history occurred when Monk found himself face-to-face with Nunn late in season six. Unfortunately, before Monk was able to learn more about who Nunn worked for, Nunn was shot dead by Sheriff John Rollins, who was part of a plot to frame Monk for Nunn's murder. 

It's hard to avoid being on a list like "Monk's Greatest Villians" when you're the man who detonated the bomb that killed Trudy. At least, in the end, justice was served… right?

If there was an episode that truly pulled at our heartstrings, it was the memorable season four "Mr. Monk and Mrs. Monk." The concept of someone you love somehow still being alive despite rumors to the contrary after years and years is something we can all get behind. Unfortunately, fans know how this story ends: "Fake Trudy" was nothing more than yet another cruel scam to undermine Monk's efforts to get to the bottom of his wife's untimely death.

The decision to cast Melora Harding (who played Trudy) as "Fake Trudy" makes the episode increasingly difficult for fans to watch; seeing Monk's emotional state crumble as he processes what he's seeing is heart-wrenching. Only by the end of the episode do we find out that Monk knew it wasn't the "real" Trudy – thanks to a visit to his wife's grave, he still felt the pain and sense of loss. 

Regardless, "Fake Trudy" died in Monk's arms – that undoubtedly makes "Fake Trudy" one of the greatest villains just for the mental anguish Monk went through. It's hard enough trying to track down your wife's murderer – having a lookalike die in your arms is a nightmare.

Hal Tucker belongs on this list for one reason: He wasn't overtly antagonizing Monk (at least not in the beginning), making his impact on Monk's story all the more heartbreaking. Introduced in the fifth season episode, "Mr. Monk Makes a Friend," Hal Tucker and Adrian Monk immediately begin a friendship after a platonic "meet-cute" at a grocery store. For arguably the first time in the series, Monk finds himself in a friendship with someone who exists outside of his neverending search for his wife's killer.

RELATED: The Many Famous Faces to Guest Star on Monk

The two men quickly became best friends, frequently taking in movie nights together – you know, normal friendship activities. When the inevitable twist is revealed (because in Monk's world, everyone must be or become an enemy) and Tucker's identity as a criminal antiques smuggler is uncovered, Monk finds himself staring down the barrel of a gun, although eventually manages to turn the tide on his one-time "friend."

Although Tucker is arrested by the end of the episode, his relationship with Monk marks an essential milestone for viewers: It serves as a reminder that Monk is as emotionally frail and damaged as ever, and if he can easily be lured into a friendship under false pretenses, then what hope does he have?

Known as the main antagonist of the entire series, Ethan "The Judge" Rickover (played to perfection by Craig T. Nelson) only appeared in the final episode, although he frequently operated as the man behind the metaphorical curtain, responsible for much of the chaos thrown Monk's way. To put it simply, the show wouldn't exist without Ethan Rickover, as it was revealed that he was directly responsible for the death of Monk's wife, Trudy, many years earlier. Rickover pulled the strings to perfection and operated as the ultimate "final boss" in Monk's character arc.

Of course, Rickover's impact on Monk lasted long after The Judge's suicide in the series' final moments. His final words were, "You take care of her!" – a veiled reference to Trudy's daughter Molly, born out of an affair with Rickover years earlier. 

Is there any surprise that Rickover makes this list? Boasting arguably zero redeeming qualities, many fans, to this day, feel robbed that Monk wasn't the person to pull the trigger – Rickover's death was welcomed, but many people believe Monk was cheated out of true justice on that day. 

Mr. Monk's Last Case: A Monk Movie streams on December 8 only on Peacock. Until then, catch up on the complete series of Monk, also exclusively on Peacock.