The powerhouse of the Five-Man Band. They are usually incredibly and unflinchingly loyal, and often they are the largest member and even more effective in combat than anyone else. (Sometimes combined.) They will often be the point man, they cause a disturbance and hold off the mooks while the others challenge the Big Bad. Of course, against stronger enemies they might end up suffering The Worf Effect; getting trounced to set up the villain as a credible threat.
Usually what holds them back from leadership is being Dumb Muscle, they know how to knock heads together but don't do much in the way of strategy. While The Leader and The Lancer fight side-by-side, The Big Guy is a One-Man Army.
Note: The Big Guy may not necessarily be the strongest in the team. They just have to be the one who, out of most duties, specializes in physical fighting.
The Big Guy on the Five-Man Band can be subdivided into five classes:
Class 1: The gruff, mean, scarred and withdrawn warrior. Could go so far as to be a Berserker, particularly of the Death Seeker variety. In an entire Five-Man Band of ass-kickers, their big guy is most likely be a class 1, ready to punch you in the face for smiling at him.
Class 2: The Gentle Giant who you don't want to push too far. Often when the other members are younger, he will be older and outside of battle is the calming element in the group, offering both experience and wisdom, or just able to pull two others apart easily.
If it's a magical setting, they may also be adept at Dishing Out Dirt or have a Green Thumb, as the "earth" element can be seen as tough, strong, and/or sturdy. Alternatively Ice may have similar connotations.
This bandmate is rarely a woman, unless the whole teamis women. The Big Girl can be classified into three subspecies:
The Cute Bruiser: she who packs a surprising amount of punch. Traditionally a little girl, but can be stretched to any woman who is not obviously of amazonian stature. May be a martial artist or some other form of athlete. In cases of truly great strength, she may be a cyborg, Robot Girl, mutant, alien, possess Charles Atlas Superpower, or have some other justification for unusual power. Usually just as cute and/or pretty as more typical female characters. Male versions of the cute bruiser exist too.
Alternatively and more unusually, she's a Giantess, and thus plainly strong. She's rarely masculine but rarely conventionally attractive. (There's also nothing stopping her from being a robot, mutant, alien, etc. It's just that the surprise is gone.)
Piotr aka Colossus of the X-Men is the poster child for Class 2, who replaced Class 5 Genius Bruiser Hank McCoy / The Beast when he first appeared. Sometimes they're both on the team together...at which point the bad guys should generally start running.
Atom Smasher (formerly Nuklon) was the Big Guy and Gentle Giant for the original Infinity, Inc., an incarnation of the Justice League of America and much of the Justice Society of America, until he did a Face Heel Turn (he later turned back). His godbrother Damage has more or less taken up this role in the current JSA, who until Gog repaired his face was definitely a Class 1. Atom Smasher is presumably a reserve member and still drops in on occasion, usually when the team takes on Black Adam.
Whenever the Hulk teams up with other heroes, he generally fulfils this role.
The exception being the Warbound, where Hulk is the Leader and Korg is the Big Guy.
Molly from Runaways is a very typical Cute Bruiser.
Channon Yarrow of Transmetropolitan is a relatively subtle Big Girl— to be fair, being physically imposing by comparison with Spider Jerusalem isn't that hard. Still, she doesn't easily fit into any of the subtropes.
Marv was designed to be one of these. In Frank Miller's words: "Conan in a trenchcoat". He's seven feet tall, he's at least four feet wide, he's big and boisterous and strong. When he teams up with Dwight in "A Dame To Kill For" it's especially apparent.
Bully, a non-nazi skinhead from German comic Rudi.
Heracles takes on this role when part of an ensemble.
The special character Nork Deddog in Imperial Guard Codex of Warhammer 40000 is definitely a Class 2. While he is proud of his many shiny buttons and is a genius in Ogryn terms (N is for Nork), he remains in the Guard because of the content feeling fighting alongside his fellow troopers gives him.
Bun-Bun from Sluggy Freelance is one of these, despite being the smallest (and arguably cutest) member of the cast. He's the Killer Rabbit trope cranked up to eleven and given a Hammerspace switchblade and glock.
Mr. Mighty from Everyday Heroes, at least in his current team. He could be either Class 2 or Class 5; in practice bouts with his teammates, he wins by strategy rather than pure strength. Has often fought solo in the past, and has learned to outsmart opponents.
Justin, while not yet physically adept as Grace or Nanase, shows signs of becoming a Class 2 as of New and Old Flames giving him non-illusory magical powers, seemingly related to punching, when he is not acting as a back-up The Smart Guy or The Chick instead.
Torq, the Half-Orc fighter from the Critical Hit Podcast, is a bit of #4, though he's not always Boisterous. He is almost a Cloud Cuckoo Lander normally, but becomes a whirling, athletic menace in combat. His player, Matthew, specifically statted him this way.
Sura Verandis of Ilivais X. Even his Avespia is heavier and more melee-oriented than the others.
Lancer of Team Kimba in the Whateley Universe. He's the Flying Brick with no magical or psychic powers. He's the strongest and toughest team member and the one most likely to step in front of an attack to protect someone else.
Maine of Red vs. Blue is a classic Class 1. He's huge, terrifying in combat, and can take unbelievable amounts of punishment. And he doesn't much care if you have a nice day or not.
Tex and Sheila/FILSS also apply. Both pretty well fit in the Giantess category; one is only ever seen in full body armor and is an AI in a robot body anyway while the other is literally a tank (and a Cool Ship). Sheila is undeniably the toughest and best fighter in the series (she's a tank and a spaceship with an enormous gun), but Tex is one of the best as well.
In historical armies, grenadiers were selected among the strongest and largest soldiers. Early grenades were softball-sized iron balls filled with explosives, and were thus very heavy; the grenadiers, who were responsible for throwing them, needed to be tall and strong enough to hurl them at the enemy without risking the lives of their comrades.