Why Can't You Say Good Night?

Parting words, coming after drugging someone but before the victim hits the ground. May take the form of a Preemptive Apology. A kind of Pre Mortem One Liner without the actual, y'know, death. The last words from the guy they drugged are Parting From Consciousness Words.

Trope name comes from Tony Basil's "Mickey".

Film
"Hudson Hawk: Hey, this doesn't taste like cappuccino.
 * Hudson Hawk.

Anna: Oh. I guess I put too much ethyl chloride in it.

Hudson Hawk: [collapses]"

"Casanova Frankenstein: "It's a chloroform-deploying portable enticement snare."
 * Mystery Men: Right after Captain Amazing asks whether what he just picked up is not evidence, it shoots out a cloud of pink smoke:

Captain Amazing: "... - Ah, dang!""

"Irene: I told you to let it breathe."
 * Sherlock Holmes

Live Action TV
"Ethan: "You... probably shouldn't have drank that so fast...""
 * Dexter: explains how ashamed he was at accidentally leaving one piece of evidence as the Ice Truck Killer.
 * And, of course, Dexter himself often whispers a one-liner to his victims right after he slips them the needle.
 * Played with on Lost. was handed what was told to her to be a glass full of tranquilizers.

"Mohinder: "I already have you, Mr. Sylar.""
 * Heroes: Mohinder to Sylar

"The Baby-Eating Bishop of Bath and Wells: Drugged! By God!
 * Black Adder:

Blackadder: By Baldrick, actually, but the effect is much the same."

Manga and Anime
": Good night,."
 * Tiger and Bunny

Video Games
""Nothing personal. Can't risk you going berserk and getting Lisa killed.""
 * Mona Sax, right after drugging Max Payne:

Web Comics
" : T-tut mir leid. ("I'm sorry.")"
 * After Jordi is drugged in Cuanta Vida:

"Lucrezia: Not poison, silly. I'm one of the good guys now, remember?"
 * In Girl Genius:

Western Animation
""You'd be surprised at the amount of chemicals the average cigarette contains.""
 * The Venture Brothers:

""Logan, buddy! It's me, Deadpool! I shot you.""
 * After a certain mercenary tranquilizes Wolverine in Hulk Vs Wolverine...

""Tell me, Batman... What question can you never answer "yes" to? Are you asleep?""
 * In The Batman, after the Riddler sprays Batman with knockout gas: