Villain Cred

Whether you consider it short for villain credentials or villain credibility, it's a measure both of how much respect a villain gets among his fellow rogues and of how credible a threat the do-gooders and the authorities consider said villain to be. It's earned through successful completion of bold, daring and devious deeds; in other words, nothing so pedestrian as robbing bank or holding up a liquor store will suffice. It can also be lost in a heartbeat if one runs afoul of meddling kids and their talking dog.

A specific villainous version of a Karma Meter. Often a major motivation factor for a Card-Carrying Villain or Noble Demon.

Examples of Villain Cred include:

Comic Books

One Silver Age Flash story has the Mirror Master get upset that he's only ranked as the third most successful criminal in the prison newspaper, so he breaks out to commit more crimes in the hope of raising his standing.
A Silver Age Batman story has the Joker and Clayface commit crimes using each other's M.O.s so that each can claim the title of Public Enemy #1.
- The same basic gimmick was used in Poison Ivy's debut story in the 1960s, where she arranges the capture of three other female criminals—Public Enemy numbers 1, 2, and 3 -- so that she can step forward and take credit for various previously unsolved crimes.
- And used again in a story in the 1970s where rumors of Batman's murder sweep through the underworld, prompting the villains to assemble a Joker Jury of their own to evaluate the Villain Cred of the various supervillains (ranging from The Joker to Lex Luthor to Catwoman) claiming to be Batman's killer.

Literature

Prince Xizor - from Shadows of the Empire - has the stated goal of replacing Darth Vader as Palpatine's right-hand-man by proving himself superior to Vader.

Live Action Television

A consistent element through Buffy the Vampire Slayer and Angel. The Watcher's Council records the exploits of demons and vampires, and the underworld community in general seems to have pretty good word of mouth. Angelus had particularly good cred, something Angel occasionally traded off of. At one point Darla and Drusilla managed to attract a group of demons to serve them simply by introducing themselves (and de-earing one person who'd never heard of them). Spike had a particularly good reputation for having killed two slayers despite being barely two hundred - or 126, or a vampire for 120 years. Several enemies come to town specifically because killing a Slayer would be good for their reputation.

Videogames

In the Evil Genius game, this is your genius' Notoriety, which increases as you sucessfully complete Acts of Infamy.
In the videogame adaptation of The Godfather, you get "respect" points that make you more powerful. Acts that earn you respect range from helping shopkeepers and bribing police officers to murdering enemy gangsters and blowing up their safehouses.
In the Saints Row series, you get "respect" which can be used to go on missions.
The Overlord series: Not only are you explicitly a villain, but you get ranked on how evil you are via Karma Meter, ranging from Complete Monster territory to Affably Evil.
Liberal Crime Squad has Juice, which represents your street cred as a member of La Résistance and goes up as you slaughter hordes of soldiers, cops, and workers who refuse to join labor unions.
Occurs in City of Villains. You can even give it to other people, because you're increasing their reputation at the cost of your own due to "selling out"
Demons from the Disgaea series tend to be rather concerned about their reputation for "evilness," but most of them aren't very good at it beyond things like not washing their hands or cutting class. This is probably for the best, since demons who are good at bad (e.g. Baal and Zenon) are kind of scary.

Web Original

In Dr. Horrible's Sing-Along Blog, Dr. Horrible's primary goal through Act I and Act II is to earn enough cred to get into the Evil League of Evil. He eventually succeeds...but at a horrible price.

Western Animation

Kim Possible learns that her Evil Counterpart Shego used to be part of a superhero team, and uses that to blackmail her into helping her defeat this week's villain:

Kim: Because if you don't help, I'll tell the the world you used to be a good guy.
Shego: You wouldn't!
Kim: I've got a website, and I'm not afraid to use it.
Shego: Ugh, my evil reputation would be shot!

After much evil perpetrated around the Tri-State Area, Dr. Doofenschmirtz rescues one kitten from a tree, and risks the complete loss of his evil-genius status.
- His worst Christmas is also his best because it was the first Christmas bad enough to give him an excuse to hate the holiday. Apparently, not hating Christmas, even if you don't like it either, is nearly as harmful to Villain Cred than rescuing a kitten.
Most of the plot of the 2019 Harley Quinn series is about Harley trying to upstage the Joker and gaining respect among other super-villains.