For more than 20 years, NCIS has been the gold standard of crime procedurals, blending sharp investigations with rich character arcs that keep fans glued to their screens. But one thing that has always defined the series is its villains. A great antagonist does more than commit crimes—they test the team’s limits, break their hearts, and sometimes even blow up their world.
As Season 23 introduces us to its latest threat—the mysterious Black Mask Killer—viewers were bracing for a villain unlike any before. After all, the chilling string of murders and the eerie calling card set a sinister tone. And while the Black Mask Killer is undeniably awful, here’s the truth: this villain doesn’t even come close to the worst NCIS has ever seen.
Why? Because the NCIS universe has given us masterminds who shattered trust, terrorists who struck at the team’s core, and killers whose mere presence turned episodes into television history. The Black Mask Killer feels more like a formulaic shadow than a true monster. They lack the devastating personal connections, intricate psychological games, and sheer audacity that made the great villains unforgettable.
To prove it, let’s dive into the ultimate list of NCIS’ 10 most diabolical villains—characters so evil that fans still shudder at the mention of their names.
10. The Privileged Killers (Tommy and Christopher)
Season 16 brought us two of the most disturbingly arrogant murderers in NCIS history. Tommy and Christopher weren’t terrorists or spies—they were spoiled, entitled sociopaths who killed simply because they could. Their casual cruelty and total lack of remorse were chilling, proving that sometimes the most terrifying villains are hiding in plain sight, behind wealth and privilege.
9. Jonas Cobb (The Port-to-Port Killer)
Jonas Cobb wasn’t just a killer; he was a ghost in the machine. Known as the Port-to-Port Killer, Cobb left a trail of bodies across state lines, taunting the team at every turn. His precision and ability to vanish made him one of the show’s most nerve-wracking adversaries. Cobb was dangerous not only because of his military training, but because of the psychological torment he inflicted on the team.
8. Trent Kort
Sometimes the most dangerous enemies wear suits and carry government credentials. CIA operative Trent Kort wasn’t your traditional murderer, but his actions led to bloodshed and heartbreak. He orchestrated betrayals that cost lives—including that of Eli David, Ziva’s father—and his morally bankrupt scheming kept Gibbs and the team constantly on edge.
7. Thomas Morrow
Few betrayals cut deeper than this one. Once the Director of NCIS, Morrow turned out to be a traitor tied to a shadowy organization. His corruption wasn’t just shocking—it was catastrophic. Morrow’s decisions caused deaths, shattered trust, and made it painfully clear that even those at the highest levels of authority could be rotten to the core.
6. The Phantom (Phillip)
The Phantom was the stuff of nightmares: a civilian hiding in plain sight while committing unspeakable murders. For years, his crimes haunted Gibbs, lingering like an open wound. When the truth finally came out, the reveal was terrifying. Phillip wasn’t just a killer; he was a reminder that evil can wear the mask of normalcy, blending into everyday life until it’s too late.
5. Saleem Ulman
Terrorist. Brother. Monster. Saleem Ulman wasn’t just a villain; he was a personal demon for Ziva David. His ruthlessness and willingness to kill—even those closest to him—made him a constant source of dread. His existence pulled Ziva into a spiral of pain and vengeance, making every encounter a high-stakes emotional battlefield.
4. The Lizard (Malia)
Some killers use guns. Others use words. Malia—known as The Lizard—was a master manipulator who weaponized psychology with terrifying precision. She didn’t need to pull a trigger to kill; she dismantled her victims’ minds until they destroyed themselves. Cold, calculating, and eerily calm, Malia remains one of the show’s most haunting antagonists.
3. Sergei Mishnev
If revenge were a person, it would look like Sergei Mishnev. The half-brother of Ari Haswari (another name on this list), Mishnev waged a one-man war against Gibbs, aiming to make him suffer for Ari’s death. Every move Sergei made was personal, and that relentless vendetta turned him into a ticking time bomb the team could never fully predict.
2. Ari Haswari
The villain who changed NCIS forever. Ari wasn’t just a terrorist mole—he was a monster who murdered Agent Kate Todd in cold blood, delivering one of the most shocking TV moments of the 2000s. His betrayal was intimate, his motives twisted, and his actions left scars that shaped the show for years to come. Ari wasn’t just a villain—he was a catalyst for the birth of Ziva David and one of NCIS’ darkest eras.
1. Harper Dearing (The Chameleon)
No contest: Harper Dearing reigns supreme. A brilliant, vengeful former naval officer, Dearing blamed the military for his son’s death and unleashed hell on NCIS. His attacks weren’t random—they were surgical strikes designed to obliterate the team’s sense of safety. When he detonated a bomb that destroyed the NCIS headquarters, nearly killing several beloved characters, it became one of the show’s most explosive and unforgettable storylines. Harper Dearing didn’t just hurt the team—he blew their entire world apart.
Why the Black Mask Killer Falls Short
Compared to these monsters, the Black Mask Killer feels… hollow. Yes, they’re dangerous. Yes, they’ve left bodies in their wake. But they lack the emotional stakes, the psychological complexity, and the long-lasting scars that define NCIS’ greatest villains. The ten names above didn’t just challenge the team—they changed them forever.
The Black Mask Killer is just a chapter. These villains? They were the book.
