The Beagle Boys in the Scrooge McDuck comics and DuckTales.
The X-Men books gave us this trope right out the gates in the original Brotherhood of Evil Mutants, who were pretty silly until character development set in. Later the nineties gave us the Dark Riders, a team of mutant mercenaries who follow the strong while ironically not being very strong themselves. They attached themselves to Apocalypse, ditched him for Stryfe and then joined up with Stryfe's maybe-son Genesis, but one thing they never picked up over the years was a shred of respect. Most of them were killed off unceremoniously by Wolverine, though a few survived to make sporadic D-list appearances over the years.
Before he lent his name to a summer blockbuster, The Fallen created one in the second volume of Transformers: The War Within. Decepticon mystics Bludgeon, Mindwipe, and Bugly were given vague mystical power upgrades and charged with gathering a team of (seemingly arbitrary) Transformers so that The Fallen could attempt to summon Unicron.
Manute in Sin City had a QMBS with him in Big Fat Kill which consisted of a midget, a wise-cracking Neo-Nazi, and an old guy who can make people feel pain just by touching them. The Irish mercs from the same story might also count.
In the Sonic The Hedgehog comics, there's the Destructix - composed of Lightning Lynx, Sergeant Simian, Predator Hawk, Flying Frog, Drago Wolf, and Sleuth Dawg - a group of incompetents who have worked for various Big Bads over the years, usually getting their butts kicked in the process. Recently, Drago left to work for Dr. Eggman and Sleuth retired, handing control over to Fiona Fox, who apparently has big plans in the works (which so far consist of breaking her boyfriendScourge out of prison so that he can take charge of the gang).
Recently, Dr. Eggman got a new group of enforcers in the form of the Metal Series — a group of Evil Knockoffs of several of the main heroes, led by the recently roboticized Mecha Sally.
The Angel Gang from Judge Dredd are a clan of murderous rednecks, each completely psychotic, yet also gimmicky and weird. Pa Angel is the most normal, but is still a vicious killer who treats his boys with love and devotion, yet also raised them to be brutal criminals. Junior is a gunslinging, grenade-chucking Serial Killer who is constantly begging for permission to kill people. Link is a hulking brute who dresses like a stereotypical biker and had to be kept chained up as a kid. Mean Machine is a homicidal cyborg who headbutts people to death. The weirdest by far is The Fink, a ghoulish mutant who lives in a hole in the ground and whose only friend is a rat wearing a bowler hat.
Despite supposedly being an elite squad of assassins from the League of Shadows the Seven Men of Death are incredibly quirky with weird ineffective primary weapons. In Red Robin Tim notes this, pointing out that Whip's whip and Maduvu's claw-like fingernails do not pose much of a threat against people with significant martial arts training and body armor. He also quickly decides Detonator is incredibly annoying and dangerous since the man uses hand grenades in close combat.