Bad Guy Monologue

The tendency of some "geniuses" to tell people of their master plan to destroy them before actually doing it. This usually results in the plan being foiled and said "evil mastermind" getting their comeuppance.

Multiple James Bond Films.

"Oh great, ol' Goldfinger's got diarrhea of the mouth again and is giving his 'Bad Guy Monologue' before he saws the guy in half with a laser..."

"One of these days that's going to bite him in the ass."