Ranking the Most Horrific Major UnSubs on 'Criminal Minds' (PHOTOS)

Meredith Jacobs

The BAU doesn't always get the job done (right away, at least).

Over 14 seasons of Criminal Minds, the same UnSub has occasionally appeared more than once. And in some cases, those offenders leave a lasting impression on at least one member of the team. In fact, Season 14 has already teased one such serial killer will return in the final season, as Everett Lynch (Michael Mosley), introduced in Episode 13, "Chameleon," escaped after leaving an unconscious Rossi (Joe Mantegna) alive.

8 'Criminal Minds' Episodes That Still Haunt Us (PHOTOS)

8 'Criminal Minds' Episodes That Still Haunt Us (PHOTOS)

From BAU members being tortured to 'North Mammon,' we can't forget what these UnSubs did.

But we have yet to see how he'll be remembered when his time as an adversary for the team ends. In the meantime, TV Insider has ranked the major UnSubs — some are Big Bads, while others will always be remembered by fans for the heinous acts they committed in their episodes — of the CBS drama so far from most to least horrific and memorable.

Click through the gallery to see where killers like Mr. Scratch, Foyet, and Frank land.

Criminal Minds, 15th and Final Season, Coming Soon, CBS