In Naruto, the main character fits this to a tee, with one noticeable (read: glaring) exception when against the Demon Brothers. Before and after that, he pretty much leaps into danger with a smile, ready to punch or (as necessary) headbutt his enemies without fear of his own safety. He matures somewhat post-Time Skip though. Who could have predicted that ninjas would leap out of hiding and attack you?! It seems so un-ninja-like!
Rak from Tower of God. In a test where the wrong decision would cost his head, he figures that the lack of clues must have meant that he had to gamble. That was one of his smarter moves.
One Piece: The hero Monkey D. Luffy is pretty much the embodiment of this trope. He charges headlong into dangers great or small without once thinking of his own wellbeing. This includes leading a small army in a siege against the World Government stronghold Enies Lobby, punching out a World Noble, who are treated as walking gods, engaging in a battle in the Alcatraz known as Impel Down, heading to the Marine Headquarters with a large group of dangerous convicts to fight the entire Navy!
One of the only things Luffy is shown to be scared of is his own grandfather Marine Vice-Admiral Garp, due to the fact that he was raised by him in near-constant Training from Hell and Punches of Love.
Saint Seiya: The hero Pegasus Seiya has no sense of self-preservation whatsoever, often veers into Too Dumb to Live territory and will happily sacrifice his life on multiple occasions for his friends/goddess. When asked how he manages to keep on living, he most often responds with 'I don't know'.
Tai gets shades of this after being told that everything in the Digital World is made of computer data, including him. When it finally gets drilled into his head that if he dies here he still dies for real, he goes to the opposite extreme and become petrified with fear.
While Motoko Kusanagi of Ghost in the Shell: Stand Alone Complex doesn't do this in the way ascribed to most shonen heroes, she is still equally guilty of it. As the episodes go on it becomes more and more clear that she does things even her hardened comrades consider incredibly reckless, and one loses count of the number of times she nearly gets herself killed over the course of the series. It's almost a running joke that Batou will specifically tell her to "not do anything stupid" and she'll do it anyway.
In Parasyte, despite repeatedly stated as incapable of feeling human emotions, the parasites obviously care about their well-being enough to avoid any unnecessary danger (even showing visible fear on occasion). The only parasite who fits the bill is Mr. A, the lover to fellow parasite, Reiko, who admits that he is "not one of our smart ones". Indeed, Mr. A is repeatedly shown to have no capacity for subtlety or deception, even using his shapeshifting abilities in front of public by reasoning that he can get out of trouble by fighting, running away or changing into a different form. This comes to bite him in the ass HARD, as his open attack on Shiniji and his parasite companion, Migi, leads to him getting critically wounded and then disposed off by Reiko when he threatened her undercover lifestyle. At one point, during his attack on the school, when he tried to punch a random student, he missed and punched the wall which completely and permanently shattered his (human) arm.
Tengen Toppa Gurren Lagann: As seen in the page image, Kamina challenged a Humongous Mecha when armed with nothing but a katana. Later he confides in Yoko that he knows exactly how stupid he was being at that time but he did it anyway in order to inspire Simon.
The Green Lantern Corps are supposed to be fearless. Taken literally, that means they're, well, dangerously insane. Of course it's understood that "fearless" is an emphatic way of saying "courageous". The Green Lanterns are not, in fact, "The Men [and Women and Nonsexual Aliens] Without Fear"; rather they have the ability to overcome great fear, and in that ability find the power to wield the Green Lantern Ring.
Sometimes the description has been taken more literally than other times; one currently-ignored story had it that rings removed all fear from new Green Lanterns. Canonically, the rings now state that the owner can "overcome great fear".
However there is one Lantern that's insane, to the shock of his partner (who just thought he was a Cloudcuckoolander).
Depending on the Writer .... there was a Green Lantern/Flash story by Mark Waid, which made much of the fact that Hal Jordan had never experienced fear, until he thought Barry's life was in danger because of him.
Similarly, Daredevil is called The Man Without Fear, though this may be because of his name. In truth, he doesn't seem to have many fears, as befits a blind man who goes out superheroing...but usually, those few he has are found and exploited by anyone who can manage to become the Big Bad of an arc.
Once in a Marvel Comics Presents story arc, this trope was taken literally with him. That was when an alien parasite who feeds on fear tried taking over various Marvel UniverseSuper Hero characters, only to be driven out each time by them overcoming their fears. In desperation, the starving parasite tried taking over a random human, only to die when he discovered to his horror that this human had no fear, and that turned out to be Daredevil.
In Astérix and the Normans, the titular Normans literally don't know the meaning of fear, even as children. The Gauls teach them, by making their awful bard Cacofonix play the bagpipes at them.
They came to Gaul to learn fear because they heard "Fear gives you wings", and took it literally.
Deconstructed with Mei in Game Theory. Due to being from a berserkerlineage, she lacks a functioning fear response, which causes her to pull all kinds of crazy, reckless stunts that put herself or others in danger. It's treated as a mental disorder, and she eventually starts taking medication that mitigates the problem.
Young Simba in The Lion King gets a speech to this effect when he goes into the elephant graveyard to prove how fearless he is only to be accosted and nearly eaten by hyenas. Darth V... — I mean, Mufasa explains that being brave doesn't mean he doesn't have fears, only that he overcomes them, and this becomes a running theme for the film.
Forrest Gump is this when he runs through the jungle in Vietnam rescuing his comrades, being completely oblivious to the bullets and explosions around him.
Batman in The Dark Knight Rises initially has no fear of death, which he thinks gives him power but is in fact why he can't find the motivation to escape Bane's prison. He needs to find something to be afraid of or he'll be useless. Bane points this out by saying, "You don't fear death. You welcome it. Your punishment must be more severe."
Skylar Lewis in Girl vs. Monster, but she later develops a sense of fear and grows out of this.
Done unintentionally in most James Byron Huggins novels. Even though most of his protagonists are Badass Normals, when your opponents are ancient Egyptian undead sorcerers, giant shape-shifting Nephilim, prehistoric Hulks, a genetically-engineered dragon, and Satan himself, for them fear is never the appropriate response, and every time, they win against these threats, but the first two acts they don't react with fear.
In Sandy Mitchell's Cain's Last Stand, Ciaphas Cain tells the cadets that he is afraid, in order to urge prudence on them. But when he describes himself as a Dirty Coward, Amberley Vail cites that a brave man is one who overcomes his fears, not one who has none, to say that Cain may not be giving himself enough credit.
At one point, earlier, Cain's aide Jurgen offers to come on a mission. Cain is not sure whether this is courage or being too stupid to realize the danger. Amberley Vail, having seen much of Jurgen over the years, isn't sure either.
Jenit Sulla, a Leeroy Jenkins who lads her men into heroic charges no matter what the sensible action. Her unit takes the highest losses of the regiment, but also has the highest morale.
In William King's Warhammer 40,000 novel Space Wolf, Ragnar is unable to tell whether the nightgangers attacking them are that brave or that mindless.
In Grey Hunters, when one Marine speaks of a heroic death, he is rebuked for not knowing the difference between heroic and stupid.
In Ben Counter's Warhammer 40,000Horus Heresy novel Galaxy In Flames, Tarvitz explicitly thinks that while it is said that Space Marines know no fear, the truth is that they are trained to master it, not to not feel it.
Fearless by Francine Pascal is about a teenage girl unable to comprehend fear.
In Terry Pratchett's Wintersmith, Granny tells the Nac Mac Feegle that they need The Hero to go to the underworld, because they themselves would not be afraid of doing it, and The Hero needs to be — so she sends them after the Baron's son Roland, who would be afraid.
Other characters are shown to be almost fearless as well, Cohen and his 'horde' foremost among them. Ridcully and Vetinari are also practically without fear, but they are far from foolish.
In Unseen Academicals, Dave Likely, at least in Trev's eyes. Nutt points out that he was only human, and furthermore people who did foolish things that could kill them have been important to humanity.
In Night Watch, Vimes describes Lord Rust this way. "He thought idiot stubbornness was bravery."
In C. S. Lewis's The Voyage of the Dawn Treader, when Lucy agrees to go into a magician's tower for invisible beings who are threatening to massacre them, and the boys can't dissuade her, the boys appeal to Reepicheep, confident that he will tell her not to do it in order to save them. Reepicheep, however, does not play the Fearless Fool: he observes they have no hope of saving her, and that she is not being asked to do anything dishonorable, so he will not speak against it. The boys are rather embarrassed.
In Patrick Rothfuss's The Name of the Wind, Chronicler tells Kvothe that they say he's fearless. Kvothe disclaims: only priests and fools are fearless, and he's not been on good terms with God.
The ogres of Xanth are famous for being too stupid to fear anything. But this is played with—it combines with their great strength to ensure that every living creature smarter than them (and that's everyone, including a number of plants) fears them. Even dragons know they can't match the sheer power-to-weight ratio of an ogre and that an ogre wouldn't be afraid of coming after them, and avoid picking fights.
In Jim Butcher's The Dresden Files novel Blood Rites, Trish/Trixie is not afraid of getting blacklisted because she's so dumb she really think she's indispensible.
In Death Masks, several warnings get thrown about, about confusing courage with stupidity.
In Blood Rites, when he is rescuing the puppies, one rears up in the box to bark at their former captors. Harry describes it as either more brave or more stupid.
In James Swallow's Warhammer 40,000Blood Angels novel Deus Encarmine, after an attack that drove many Blood Angels into the black rage — Unstoppable Rage — that resulted into their horrible deaths, Arkio accuses veteran Blood Angels of being afraid. They counter that they had all seen those deaths and are horrified and, yes, afraid. Sachiel claims that dying for the Emperor ought to negate that, but Arkio concedes that they would not be human if they did not feel as they did — and weeps Manly Tears over the deaths — before urging them to fight anew.
Being a Hero, he didn't know the meaning of fear, just as the average person doesn't know the meaning of the word fourmart* . * polecat
Later, this is invoked several times with the observation that what he felt couldn't really, therefore, be fear.
The entire Kender race from ''Dragonlance' has this reputation. For many, it's deserved.
In Dan Abnett's Warhammer 40,000Gaunt's Ghosts novel Blood Pact, Kolding plays possum when Maggs goes berserk and attacks him. Gaunt says this was wise; Kolding says it was not very courageous. He had survived a Blood Pact attack by the same method as a child — the sole survivor.
The second-in-command in Moby-Dick tells the crew a fearless man has no business being on a whale hunt.
In City of Ash, Jace gets a Fearless rune put on him by Clary. After a few minutes of fighting The Legions of Hell, he notes that the rune might be a little bit of too much of a good thing. In particular, he notes how blase he was becoming in regards to injuries.
In The Pillars of the Earth King Stephan went into Battle and was Fearless but because of that, he didn't retreat when necessary and was captured.
Marvin Russell in Tom Clancy's The Sum of All Fears. At first, the terrorists using him as a useful fool are impressed by his fearlessness, but they quickly realize that they are dealing with a crazy person. (Doesn't stop them from still using him as their fool, though.)
In The Book of Atrix Wolfe, they send off Saro to deliver the tray of food to the prince in his half-ruined and haunted towers, on the grounds she wouldn't understand it enough to be afraid.
In The Riddle Master Trilogy, Morgan had, in the backstory, casually won a riddle game where hundreds of others had lost their lives. He came home with his reward (a crown) and hid it under the bed because he wasn't sure that he wasn't a complete idiot.
In The Forgotten Beasts of Eld, Sybel is too young, and too powerful to know fear. She proves the fearless part when she summons The Rommalb, a creature which destroys any who fear. She proves the fool part when she continues to steal Spell Books from other wizards, despite Maelga's warnings.
Michael is this in the first book of the Knight and Rogue Series. Any point in later books where he chooses to flee rather than fight includes a line about Fisk having finally gotten it through his skull that in some situations it's a much better idea to run.
In Rick Cook's Limbo System, Billy Toyodo is unafraid of death because he thinks life is just a computer simulation and he'll just get another run through. The captain feels ashamed to ask him to volunteer for something dangerous because of it. (Still does, though.)
Used as the twist in Rowan of Rin. John is beaten by the mountain not because he was afraid, but because he wasn't and should have been. Exhausted and slowly freezing he realises that Sheba was right, only fools do not fear, and admits this to Rohan.
In A. A. Milne's Winnie-the-Pooh, when Pooh has made a hum about Piglet, Piglet feels honor-bound to point out it's not quite true, he was frightened, and Pooh tells him that it's the best kind of courage.
In Jack Campbell'sThe Lost Fleet novel Invicible, when asking of Jane Geary why she changed, Geary explains to her that he was afraid, and her brother was afraid, while making their heroic stands.
Gaia Moore of Fearless is this. Having been born without the capability for fear, she repeatedly finds herself in over her head because she lacks the ability to judge that a situation is beyond her.
In Lois McMaster Bujold's Vorkosigan Saga book Captain Vorpatril's Alliance, Ivan charges a man with a stunner, and Tej pronounces him either very foolish or very brave. Ivan explains that it was his stunner, which is set up so only he could fire it.
One version of Plato's Laches argues the definition of cowardice, courage and recklessness, illustrated by a soldier dropping his sword so he can better cover himself with his shield as he runs, the soldier facing the enemy with sword and shield, and the soldier throwing his shield behind him so he can get to the part where he stabs people faster.
Live Action TV
An early episode of Star Trek: The Next Generation explicitly references the trope, even though it doesn't show an example of the character in that episode. Wesley is worrying about the final test for his Starfleet Academy entrance exam: a psychological test designed specifically to stoke their fears and test how they face them. Worf helps him, much to Wesley's surprise—he saw Worf as the bravest man on Enterprise, and thought that meant he had no fear. Worf's response seems to echo the trope name quote: "Only fools have no fear." He then explains that even Klingons, known as a "fearless" warrior race, know fear, but only those who overcome it ever go on to greatness.
A later episode had this Trope explained in an anecdote by Kahless, who's basically the Klingon Messiah. Once, Kahless was staying in a village that was about to be ravaged by a powerful wind storm. All the Klingons who lived there took shelter in a cave, save for one man who stood at a cliff facing the storm. When Kahless asked why the man didn't hide with the others, he replied, "I will not run away from this danger. I will stand here and make the wind respect me." Kahless honored his wish and went inside to hide. When the citizens came out the next day, they quickly found the man's body among the wreckage. "The wind does not respect the fool."
In Red Dwarf, Lister has his fear removed by the polymorph beast that feeds on emotions. He wants to charge in recklessly at the beast and volunteers to be the bait, so the others can kill it "while it's eating me to death".
Alan Davies on QI, whose job is to leap in with the obvious answers where a wiser panelist might hesitate. Has been working in his favor lately, as the panelists have started to assume the obvious answer will be incorrect and go to great lengths to avoid giving it — when it was correct all along, giving Alan easy points.
Arguably, Mulder of The X-Files. He tends to rush into dangerous situations without thinking, leading to several instances in which Scully has to come save his butt.
In the Doctor Who serial "Planet of the Daleks", the Doctor explains to a Thal, a fellow captive, that his heroic action of leading off the enemy was heroic despite his fear, and that everyone else who does heroic things is the same.
Raylan Given of Justified is a Badass, no doubts about it. However, he tends to let his reputation go to his head a little, and pick fights with people he really shouldn't. Like 2 giant guys in a bar, while he's wasted, or Coover Bennett.
Wagner's Siegfried. Wagner explicitly described him as The Boy Who Went Forth to Learn What Fear Was (the name of an old fairy-tale).
And it's what kills him in the end...
It is quite common that a good guy, or "babyface" is said to have "more guts than brains" (as Jim Ross would say), because they continue to fight back despite being beaten down time and again, refuse to submit to submission moves, have no problems with accepting a 3-on-1 challenge, etc.
The "Rate Tank" Kellie Skater (weighing in at 68 kilograms of pure adamantium) of SHIMMER is a heel version - she blithely walks up to every Bad Ass woman on the roster, registering no fear whatsoever as she disrespects them and challenges them to matches. Every single time, she gets obliterated - but at no point does Kellie ever catch on that she's being destroyed. She keeps on taunting her opponent and bringing the fight even if she's getting smashed against the barricades, tied into a pretzel, or back-fisted in the face.
The Imperium of Man as a whole in Warhammer 40,000 can be seen as this. However, humanity is not just a Fearless Fool, but an extremely well-armed fool, too.
The Orks too, arguably. Although the only reason for their lack of fear is they were the only race not affected by the Nightbringer, they definitely appear Fearless Fools to the rest of the galaxy.
One Genre Savvy (Insane even by Ork standards, but still Genre Savvy) ork boss knows that Orks aren't afraid to die. So, when da boyz piss him off he tears their arms off instead. THAT intimidates them.
"And they shall know no fear" — except that that would indeed make Space Marines fools. So often enough in the fluff, a character will admit that they do know fear, they just don't let it rule them.
The rule "And They Shall Know No Fear" ups the odds that the Space Marines will rally after falling back from combat. With their latest codex, it combines with "Combat Tactics" to let them escape fights they can't win, hop back to a safe firing range, and continue blasting away. Fear is just their way of knowing when they need to change tactics.
In the Deathwatch RPG, Space Marines really don't know fear. Fear that can kill humans or make them insane just makes Space Marines lose cohesion as a fighting unit. The lack of fear is one reason why Space Marines have difficulty understanding humans. The closest thing to fear that they feel is disorientation and discomfort.
By contrast, there's a universal special rule called Fearless. Combined with the "No Retreat" rulenote which has been abolished, it often causes extra casualties when a player loses a close combat.
The most famous example of "Fearless" units are Khorne Berserkers, who undergo lobotomies to remove their frontal lobes, completely removing their ability to feel fear.
Foolish are those who fear nothing, yet claim to know everything.
Brave are they who know everything yet fear nothing.
The Tyranids are similar-while they aren't capable of feeling fear, they can and do retreat if the Zerg Rush tactic doesn't seem to be working. In fact, it might be said that "fearless" in most 40K terms is not synonymous with "lacking common sense".
The vast majority of 'nids probably do fall into this trope, but only in the sense that without their psychic synapse creatures to guide they are little more intelligent that dogs.
The Necron codex explains that while they don't actually feel fear, they still need to take morale tests for pinning and such because the best tactical move would be to stay down.
Over in classic Warhammer, frenzied units often fall into this due to Unstoppable Rage - units with frenzy are totally immune to psychology effects like terror or panic and get bonus attacks, but at the same time, they automatically surge forward at enemy units, even when this would involve running through Hollywood Quicksand, over a cliff, into a necropolis occupied by swarms of the undead, or into a position where a unit of Chaos Knights led by Archaon, Lord of the End Times has a flank charge open. Of course the survivors lose their Frenzy after suffering a bad round of combat, but against some opponents that's not going to leave a whole lot of sadder but wiser units.
Also in the fantasy version, we have Dwarf Slayers who intentionally invoke this in-universe. Occasionally, a dwarf will do something that so destroys his honor (like, say, leading a troop into a blazingly obvious trap that kills everyone else) that their only recourse is ritual suicide; not quietly in their own homes, of course, but rather by finding the largest, most dangerous thing in the land and charging at it shirtless with a hand-axe. They start as Troll Slayers, and eventually move up to Giant, Dragon or Daemon slayers. Note that these aren't badges of armor; they're warnings to not come between this orange-mohawked ball of death and something large and nasty enough to actually kill them. This is because the dwarves are sostubborn as an entire race, that they're psychologically incapable of suicide in any other fashion than "at the hands of a ridiculously dangerous enemy".
Scion has Virtues that divine beings possess. Two of these are Courage and Valor. The higher your score, the more power you can draw from them... and the harder it is to resist them. If you want to act against them, you either need to fail a Virtue roll or spend Willpower. (So if you're half-dead and someone is attacked by Titanspawn, you roll Valor - and if you succeed, you have to save them even though you'll probably die trying.) This also comes with the Virtue Extremity - if you somehow manage to keep avoiding your higher Virtues, you will eventually snap and pursue them without any thought towards your own wellbeing.
This likewise shows up Exalted, where a character needs to fail a Valor roll or else spend Willpower to avoid doing something foolhardy. And if they do spend Willpower, then they'll accrue Limit, and when it finally tops off, something stupid and horrifying will happen.
Various Charms can turn even the wimpiest of losers into a Fearless Fool. One Infernal Charm in particular, Cosmic Transcendence of Valor, makes you unable to feel any kind of fear— even when you're staring at the depth of Oblivion.
One demonic, gluttonous race called the Gordians (imagine a cross between an ogre and a dwarf that has been fed on a steady diet of lard) in Palladium's Land of the Damned One: Chaos Lands are described as having eggshell thin egos and going to insane lengths to prove themselves worthy ("You call Throka coward? Watch, Throka kill Dragon!").
Hank Samson, a playable investigator from Arkham Horror has this trope as a built-in game mechanic. Normally, whenever a Player Character encounters a monster, they have to pass a Horror check at the beginning. Not Samson. Thanks to his unique "Thick-skulled" ability, he only has to pass it after the fight, only realizing what a horrifying Eldritch Abomination it was after taking some time to mull it over.
Might & Magic VIII, with the artifact Berserker Belt. It raises the Might stat to obscene levels and grants immunity to fear... at the considerable expense of both Accuracy and Armor Class. The trope is mentioned in the flavor text, describing the belt as a failed attempt to create an ultimate warrior.
Orcs Must Die!: The player character. Throughout the levels, he constantly shows no fear and continues to taunt the invading Orcs, despite the fact that the world appears doomed as there are not enough Warmages to stop the Orcs.
Old Warmage: "Now she's bound the numberless horde to her will and returns to teach the Order harsh lessons in humility and subservience. But she's in for a surprise; I'm reasonably sure my apprentice is unteachable"
The Old Warmage shows a bit of grudging respect for his Apprentice in the end, admitting that the Apprentice was the only member of the Order brave enough, or foolish enough, to sacrifice magic to save the world.
In Medieval II: Total War this is brought up in a generals speech, where he describes anyone who is genuinely not afraid before a battle as a "moon-struck fool."
Touhou Project has these in spades. Partially justified with the Spellcard rules making official fights nonlethal, but you would think that, given that fighting is still painful, to the point where even true immortals just give up rather than keep getting hurt, some fairies would learn not to die in relentless Redshirt Army wave attacks at heroines who are functionally impossible for a basic nameless fairy to kill, no matter the odds, especially since some don't even have offensive powers, and essentially can only harm a heroine by simply standing there as the heroine blindly collides with her. As a justification for the fearlessness, (if not the aggression in the first place,) fairies have lives tied to nature, and as long as nature exists, they will regenerate From a Single Cell.
Cirno deserves special mention. In spite of being a fairly weak character (normally), she proudly boasts about how she's "The Strongest" (of the fairies, which isn't saying much, as most fairies are weaker than unpowered ordinary humans), and trying to prove it by repeatedly challenging beings far more powerful than herself, even though those characters have already easily curb-stomped her in the past. Apparently, The Fog of Ages is on extra strength for Cirno, and she can't remember the numerous humiliating defeats she seems to suffer on a regular basis.
Five Waves Fury in Keychain of Creation has a Valor score of 5...and doesn't it just show. All characters have four Virtues: Compassion, Conviction, Temperance and Valor. Each Virtue is ranked from 1 to 5, with 1 being low and 5 being extremely high. In fact, a Virtue of 4 or above is overpowering, and compels someone to action (or inaction) even if they know it's a bad idea. In the case of Fury, her absurdly high Valor means she is scared of nothing, not even her Deathlord boss, The First and Forsaken Lion.
Jareth in Roommates is thought to be this in-universe. In reality he acts this way because he is so powerful that he rarely is in any actual danger (if he looks concerned Oh Crap is on the horizon) so he is a inversion.
An episode had the penguins deal with a dodo cloned from Kowalski's inventions from a feather they mistook to be from an extinct species of penguin that they wanted to fight on their team. Although the penguins found his fearlessness appealing at first, they very soon realize that with fearlessness comes a complete and utter disregard for personal safety as the dodo repeatedly gets himself killed in a variety of ways, forcing the penguins to resurrect him numerous times.
Truth in Television: one of the factors contributing to the dodo's extinction was the fact that there were no predators on the island the lived in until humans showed up. They adapted no defenses against predators and were flightless so you can probably guess how well that combination ended...
Used in an episode of The New Batman Adventures: The Scarecrow creates a toxin that removes Batman's fears and inhibitions, making him much more reckless than usual—and it doesn't stop there. The writers are savvy enough to even make him more heartless, as he doesn't fear what his own reaction will be if, say, Robin gets killed or if he breaks his one rule and murders a criminal. Scarecrow is making a point that fear is necessary, not just useful, and then in his usual mad fashion extends that to mean that he is necessary to have around.
Hank Venture from The Venture Bros. as opposed to his Cowardly Lion brother Dean. He idolized his bodyguard Brock Samson and tries to emulate him whenever he can. Unfortunately for him, Brock is an ultra-violent Bad Ass and Sociopathic Hero, leading Hank to make foolishly suicidal choices.
Danny Phantom: Jack Fenton to a tee. He has a very bad habit of rushing off into battle whenever a ghost appears. Unfortunately he's only semi-competent when it comes to fighting, being he's the Bumbling Dad and all. He's often saved either through his superpoweredson or just plain luck. Though once in a blue moon, he will show above-average skills.
Scooby-Doo: When faced with a monster Scrappy Doo always says "Let me at em!" and punches the air, while Shaggy and Scooby grab him and run.
Kim Possible: Averted with Ron Stoppable. He's still a fool, but one whose foolish exterior belies a more badass nature. It could be argued that this makes him more of a hero than the titular Kim, who really doesn't seem to fear anything (except bugs). The creators certainly seemed to think so, as by the end of the series it was pretty much all about him. It should be noted, however, that even when approached from this perspective, Kim also averts this trope, being both unrealistically brave and smart. The only reason she isn't normally called out as a Mary Sue is because Ron is the creators' favorite.
An episode of Earthworm Jim where Jim ends up in a world similar to The Wizard of Oz, where all his friends and enemies play the roles of the characters, has the Hamsternator playing the role of the Cowardly Lion... However instead of always being afraid, he never feels any fear whatsoever, leading him to do outlandish, dangerous things that almost always end with him getting injured. This includes running out in front of an (offscreen) big truck.
Invoked in Fat Dog Mendoza. As Fat Dog himself puts it, "Being fearless and being dumb usually go hand-in-hand."
Max Goof from Goof Troop is very clever, when it comes to coming up with ideas. When it comes to thinking the ideas through... not so much. Over the course of the series, he wanted to help a baby bear find its parents, go to the big city unsupervised, skate on a ramp that even a famous professional thought was too dangerous, try to save his dad from The Mafia by himself, among other things. He treats his more sensible friend, PJ, as The Drag-Along. In multiple episodes Max ends up in serious danger because he was being too careless.
Max: Remember the three rules of camping. Be clean, be courteous, and be careful. Helping this little guy is the courteous thing to do.
PJ: You let me know when we hit that part about "careful".
A Bonkers short had a messenger service with Fawn Deer as the clerk and a customer comes in wanting their most fearless rider to deliver his item. Fawn Deer notes "Our most fearless rider is right over there," and points to a grave, compete with headstone; when the customer reacts into confusion and Fawn notes in complete earnestness, "Sometimes, it's smart to show a little fear!"