Adult Humor (also called Hidden Innuendo) is a very common running gag in Animaniacs.
In Animaniacs, some Adult Humor, shows Yakko blowing a kiss and saying "Goodnight, Everybody!" These jokes were targeted for the older audiences. There was also a lot of adult-oriented content which Yakko did not point out in this show, most of which was either from Yakko himself, from a segment he was not in, or when he wasn't paying attention to the innuendo.
Looney Tunes, has adult humor too(hidden innuendo)
Minerva Mink, the cartoon mink on Animaniacs, uses adult humor in her cartoons. Because of this, the censors only used Minerva as a recurring character.
Yakko, Wakko, and Dot
Hidden Innuendos are commonly used in Yakko, Wakko, and Dot cartoons. Most of the time when someone else makes an adult joke, Yakko blows a kiss to the audience and shouts "Goodnight, Everybody!"
Plotz: Get back in your tower!
Wakko: (eats Plotz's paperweight) But, I thought you needed us to be your "scelecatary". (Yakko and Dot bounce from the right side of the screen, behind Plotz, to the left side)
Plotz: Never! And give me back my paperweight!
Wakko: Okay, but you'll have to wait a while.
Yakko: (appears out of the left side, blows a kiss) Goodnight, Everybody!
Innuendos are rare in most of the other segments, because most of the time there are no big-breasted women in the other segments. However, Warner Brothers managed to sneak in lots of innuendos too, because it's Animaniacs.
Brain: Tomorrow is the running of the Kentucky Derby. Do you know what that is?
Pinky: Um, a very large hat?
Brain: Promise me something Pinky: never breed.
Pinky: Uh, I'll try.
Pinky: Me and Pipi Longstocking, I mean what would the children look like?