The Green Lantern Corps oath is one of the most prominent examples. It's traditionally recited to keep time while charging the Power Rings, though Lanterns will also say it just to be Badass. Beyond that, several Lanterns have written their own custom oaths, and rival Corps have appeared with their own oaths, so we've filed them all away in their own folder:
With blood and rage of crimson red, We fill mens' souls with darkest dread, And twist your minds to pain and hate. We'll burn you all—that is your fate!
Aya later tries to modify it so Razer won't feel bad about having to use the oath to recharge his ring. It doesn't work, but it's a good try.
The power of the crimson red, Can lead your soul away from dread, And heal the deepest wounds of hate, Let no one else decide your fate.
Sodam Yat, a Daxamite (basically, Superman with a weakness to lead instead of kryptonite) combines the GL and Sinestro oaths as the last suviving GL (and from the sounds of it, the last surviving Lantern of any colour) in the 30th century:
The full quote is, "I'm the best there is at what I do — but what I do best isn't very nice."
Parodied in the 1980's Nightcrawler limited series, when a Wolverine-caricature started to say that what he does best is "Guzzle beer." (He actually cut himself off right after the "B" and substituted "Commit mayhem!")
Also parodied when Wolverine was reduced to a childlike, prim mentality and gave his catchphrase, "I'm the best at what I do, and what I do... is so terribly pretty!" while holding up a paper doll chain.
Dreams save us. Dreams lift us up and transform us. And on my soul, I swear — until my dream of a world where dignity, honor and justice becomes the reality we all share — I'll never stop fighting. Ever.
The Iconic "I fight for Truth, Justice and The American Way"
The Pledge of a Superman, from at least World's Finest Comics #213:
I will use this power for all the good that can be done... To work for peace... To encourage virtue... And above all, to preserve life, in all its forms... Or failing in that, to give up this power...forever!
Darkseid has officially reached this level of badass creed in the JLA book Rock of Ages.
Announcer On your knees for the Master!
The hour has come! HE has come!
Who is beyond good and evil?
Who is the prophet of Anti-Life?
Who is the Rock and the Chain and the Lightning?
All powerful! All unforgiving! All conquering!
WHO IS YOUR NEW GOD NOW AND FOREVER?
Darkseid: Darkseid is.
Of course Dan Turpin from the DCAU kinda took the wind out of his Badass Boast.
"Never compromise" was his creed, though; the Armageddon gets tacked on when... well, when it's Armageddon. For all intents and purposes.
"I am the Iron Fist. I stand before the unstoppable hordes...and I hold them back. That's what I do. What I've always done. I am the Iron Fist. I hold back the storm...When nothing else can."
John Custer: Don't take no shit off fools. Judge a person by what's in 'em, not how they look. An' you do the right thing. Be one of the good guys. 'Cause there's way too many of the bad.
Frank Drake of the Nightstalkers distills the entirety of Silver Age Superhero philosophy into four words. Do good. Fight evil.
The Golden Age Sandman, as revived in the 1990's Sandman Mystery Theatre series: "None can escape the Sandman's dark dream."
He also used to leave a poem on his defeated opponents: "There is no land beyond the law / Where tyrants rule with unshakable power! / 'Tis but a dream from which the evil wake / To face their fate, their terrifying hour!"
In the Sonic series, but most commonly the Archie comics, theres always a badass creed used to summon upon the power of one of the emeralds, usually the Master Emerald, for a specific request, usually along the lines of "The servers are the seven chaos emerald, chaos is power, enriched by the heart" followed by the request. The badass-ness of this is shown in its full height at the end of the Enerjak arc, as Knuckles and Doctor Finitevus both channel the energy of the Master Emerald and prepare to strike the other down with one energy charged punch, in a way that seems to invoke the feeling of a battle between Hal Jordan and Sinestro.
Knuckles: The servers are the seven chaos...
Finitevus: The servants are the seven chaos...
Knuckles: Chaos is power, enriched by the heart...
Finitevus: Chaos is power, controlled by my will..
Knuckles: The controller exists to unify the chaos!
Finitevus: The controller exists to enslave the chaos!
Krypto the Superdog was part of the Space Canine Patrol Agency, whose slogan is as follows: "Big Dog! Big Dog! Bow wow wow! We'll crush evil... Now, now, now!" If "big dog, big dog, bow wow wow" sounds anticlimactic, it's because it's a Shout Out to the Yale chorus ("Bulldog, bulldog, bow wow wow...")
In the Animated Adaptation, they were called the Dog Star Patrol, and it was "Dog Stars, Dog Stars, bow wow wow! Bark for justice, now, now, now!"
In The Metabarons, Bushitaka, the Castaka family code. It allows victory, or death in pursuit of victory as the only possible choices for a warrior. At any cost.
