Quotes: Underestimating Badassery

Charlie: Your new counterpart: Parson Gotti, Lord Hamster of Gobwin Knob. The more-than-perfect warlord. He is the most dangerous being in Erfworld.
Tramennis: What, behind the potato?
Charlie: I'll send you a dossier.

Dalek: SMALL HU-MAN FE-MALE SIGH-TED ON LE-VEL THREE!
Ace: Who are you calling small!? [proceeds to attack Dalek with a baseball bat]

You fools!! In battle, if you let your opponent see you're winded, it's the same as throwing away most of your chance of victory!! Watch carefully and learn the intensity of the battlefield...
WOP!
—Random Mook believing Guts to be tired during his Extreme Melee Revenge, Berserk

Loki: Enough! You are all of you beneath me. I am a god, you dull creature. I will not be bullied by—
*WHAM WHAM WHAM ... WHAM WHAM*
Hulk: Puny god.

A lot of people have thought they could handle the Undersiders.
Citrine, Worm

Castiel: Don't worry about the Winchesters.
Crowley: Don't worry about...what, like Lucifer didn't worry? Or Michael, or Lilith, or Alastair, or Azazel didn't worry? Am I the only game piece on the board who doesn't underestimate those denim-wrapped nightmares?!

"The Commander was wrong; you are dangerous! Too dangerous to leave alive!"

Jeong-Jeong: Nothing I taught you prepared you for the Avatar.
Zhao: I think I can handle a child.

Kouji Kabuto: You're not getting away, Gadlight! We're gonna settle accounts today!
Gadlight Meonsam: “You're not getting away”? Don't make me laugh, Earthling! Looks like you still don't understand the gap in power between us! Someone like you doesn't have a snowflake's chance in Hell of beating me!
Kouji: You know about all of the villains who've said that and underestimate us!? Not a Black Hole, Fallen Angels, the Mycenae, or Sphere Reactors have been able to stop us!
Gadlight: Then I'll have to shove your faces down into despair!
Kouji: Just try it! We won't hand our future to someone like you!
—Scenario 58, Third Super Robot Wars Z: Jigoku-hen

You've gone far enough. Neloth is a fool to think he could send some low life to finish me off.
Ildari Sarothril to the Dragonborn, The Elder Scrolls V: Skyrim, Dragonborn

Caitlin: Barry has superpowers. Oliver has a bow and arrow.
Diggle: Do you have any idea how many people Oliver has killed using that bow and arrow?

"You and your kind may play mortals for weaklings and fools, and that may be fitting for some, but you underestimate me."