Villains' big mouths?

A trope describing villains love to yap on and on, which proves to be their downfall. If they hadn't been yapped on like the yaps that they are, they might have achieved victory. These villains are, simply put, their own worst enemies.

Compare Nice Job Fixing It, Villain, as well as Engineered Public Confession.

Examples (all taken from Watch Mojo's video on the subject (and yes, I copied a lot of their words)):

• A Few Good Men: Lieut. Kaffee's investigation of the death of William Santiago after his incarceration at Guantanamo Bay leads him to question the base commander, Colonel Jessup, in a courtroom. But after Kaffee gets a little carried away, the judge says that Jessup doesn't have to answer any more questions. But the Colonel won't stop talking. After giving an intimidating monologue, Kaffee forces Jessup to reveal the truth (though not before Jessup famously bellows: "YOU CAN'T HANDLE THE TRUTH!"): the Colonel's orders led to Santiago's demise.
• The Princess Bride: When Inigo Montoya arrives at the castle, he has no intention of showing Count Rugen, AKA the Six-Fingered Man, no mercy after the Count murdered Inigo's father. When Inigo confronts the Count, the latter cowardly runs off and tries to sneak-attack Inigo, seriously wounding. However, instead of killing Inigo once and for all, the Count foolishly decides to gloat:
  Count Rugen: You must be that little Spanish brat I taught a lesson to all those years ago. You've been chasing me your whole life only to fail now? I think that's about the worst thing I've ever heard.
  • He gloats for such a long time that Inigo has just enough time to recover and deal the Count the long-promised fatal blow.
• The Lion King: When all is said and done, Scar murders his brother, King Mufasa, sent Prince Simba into exile, and ran the Pride Lands into ruins, all in his quest to become king himself. But when Simba returns from the "dead" to reclaim his rightful place as heir to the throne, Scar tries to turn all the lions against Simba. However, before he deals the fatal blow, he makes the fatal mistake of confiding to Simba the truth about Mufasa's death:
  Scar: And here's my little secret: (whispers in Simba's ear) I killed Mufasa.
  • The minute he hears that, Simba is renewed with energy to lash out Scar and physically forces his uncle to repeat his confession to everyone (after which they all side with Simba again):
    Scar: All right! (softly) I did it.
    Simba: So they can hear you...!
    Scar: (roaring with conviction) I KILLED MUFASA!!!
  • Then when Scar tries to push the blame away from himself and onto the hyenas ("It's the hyenas who are the real enemy. It was their fault, it was their idea!"), they demonstrate to their traitorous boss that that will be the last mistake he ever makes.

Edited by MHarrington on Feb 21st 2021 at 9:30:16 AM

You want Trope Finder for this type of query, but while we're here... Evil Gloating will be a good place to start.