Some villains in the 1990s animated series followed suit, most memorably Mr. Freeze's thugs who wore heavy, hooded fur coats. Since their employer produced pure cold, this may have been less about adhering to a theme, and more about staving off frostbite.
Joker started off with a few minions of his own, but between his financial troubles and his reputation as a Bad Boss, it was eventually down to just him and Harley.
The password for a computer program made by Power Rangers Zeo Blue Ranger Rocky was "mook." This password would be visibly typed in by a Machine Empire Mecha-Mook called a Cog in order to steal the software and create the monster Silo.
The whole concept of Mooks being easy for the heroes to defeat was even lampshaded in one episode by King Mondo, where he complained, "What's the point of building more Cogs when the Rangers are just going to reduce them to scrap metal?!" (This led to a henchman getting an idea which was sort of a new approach, but it still didn't work in the end.)
And their usefulness is lampshaded in one episode of Operation Overdrive; one of the Big Bads, Kamdor, notes that while he can create monsters, Flurious and Moltor both have armies of foot soldiers. And it's proven earlier in the episode that numbers make a big difference; if the Rangers hadn't shown up, he and his Dragon Miratrix would have likely been defeated. Kamdor subsequently brainwashes a group of stuntmen playing ninjas to fight for himself, but while they help, the spell only lasts for that one episode.
Kamen Rider has them less often, but a handful of KR series do. They'll often have design homages to the first batch, the Shocker Soldiers in the original series.
Kamen Rider Dragon Knight takes a one-shot monster from Kamen Rider Ryuki and mass-produces it.note You can tell the Ryuki footage because suddenly one Gelnewt - that's what the red minions are called, it's All There in the Manual - is a match for two Riders. It's shortly after we meet Thrust. One of the Kamen Rider Den-O movies, made after KRDK's end, then uses them! Yes, it's okay if your head hurts now. The movie was a Decade crossover, so it could be all Decade's fault (in other words, maybe they're really from Ryuki World or even an unseen Dragon Knight World.)
In the 999th and 1000th episodes of the Kamen Rider franchise, we get Mookdom taken to its logical conclusion: In Kamen Rider OOO, the main villains create the Monster of the Week from people's desires. This one's created from the rage of a former Shocker Soldier whose name actually is "Mook", who is pissed at the years and years and years of Mooks having their butts handed to them by Kamen Riders. He goes on to spawn a small army of footsoldiers from across franchise history... or rather, Yummies (OOO's monsters) in the form of them. Apparently, foot soldier job satisfaction is about as low as you'd expect... but they take pride in it.
In Kaizoku Sentai Gokaiger, we get a similar situation (though in a brief sequence), during Kaizoku Sentai Gokaiger the Movie: The Flying Ghost Ship. The Gokaigers face a multi-seasonal army of grunts who have Mook Pride. When looked down upon as cannon fodder, they insisted that they weren't just goons, they were valiant warriors of evil! They're told that they are just cannon fodder, and go on to experience typical results when the Gokaigers lay into them. They merge into a giant gestalt Mook, but quickly fall to infighting and get destroyed because, as Captain Marvelous puts it, "Once a mook, always a mook!"
Funnily enough, the main spokesmook was a Nanashi. They didn't talk in Shinkenger.
Kamen Rider has an interesting and evolving relationship with this trope. At first, it was more like other Toku series, with a campy colorful villain, his Monster of the Week, and a squad of goons that the hero(es) could usually deal with without even bothering to suit up.note What Measure Is a Mook? note: The first grunts, Shocker Soldiers, were actually explicitly reconstructed humans like the monsters, generals, and of course the riders themselves, and they had the human faces to prove it before the full-body-covering suits showed up. They were real people who got real dead when the Rider tossed them off of something high or threw one of their pointy objects back at them. This was quietly ignored long before the end of season one, and the origin of the grunts usually goes unmentioned in later series. However, in any series where every enemy down to Monster of the Week is a reconstructed human, you've still gotta figure the footsoldiers didn't grow on trees. Plot convenience decided whether they would be surprisingly competent, just a warm-up for the fight against the Monster of the Week, or even comic relief for even Butt Monkey characters to toss around. No different from the Putty Patrol. Black curiously lacked footsoldiers, Black RX brought them back. Grunts would vanish entirely after Black RX, with none of the 90s movies or first decade of Revival series having them. However, those series did have a few mass-produced enemies. They'd get demoted to Mooks in later appearances.note For example: the Roaches of Kamen Rider Blade were an all-devouring scourge. The Movie and Decade makes them Mooks; in Decade, we even get a King Mook version, the Bossroach. The Raydragoons, Sheerghosts, and Gelnewts of Kamen Rider Ryuki were just like the Monster of the Week mirror monsters: wild fauna of the mirror world, not a part of anyone's evil plan, just hungry. When you get human-sized mass-produced ones, it's less "footsoldier as opposed to monster" and more "school of piranha as opposed to one shark." However, they're mooks in Dragon Knight and Decade. In Kabuto, Worms begin in a generic form called a Salisworm, short for chrysalis. One will molt and become the Monster of the Week. If you battled a molted Worm, you'd probably be ganged upon by the unmolted ones too - even if none appeared to be around before. Then there are the cases where you get two or three of a kind acting as a collective Monster of the Week. This was popular in Kabuto. However, it would change with Kamen Rider Decade: the aforementioned mass-produced monster reuse, and crossovers with series that did have grunts, made The Powers That Be decide it was time to dust off this trope. However, it's still with a twist: usually, the Monster of the Week is often acting on its own, as or in concert with a human with a beef and access to a bad power source. The main villains have a long-term plan that doesn't much hinge on whether or not that kid gets revenge on the girls at his school for rejecting him. When the main villains are actually running the show, though, they have footsoldiers as backup. In other words, Mooks aren't comic relief anymore; the main villain's personal army showing is how you know things just got serious.
Mooks return with the Ghouls of Kamen Rider Wizard, but the villains seem to be Genre Savvy: it hasn't been stated explicitly, but they seem to know the Ghouls really have no chance of defeating Wizard, and just use them to keep him busy while they go after the Gate.
The Jaffa of Stargate SG-1. Extensive work in both canon and fanon has been done to justify this, mostly with weaknesses that could be removed once they changed sides;
Training: Jaffa are conditioned from birth to see their leaders as gods who will reward them for their service in the afterlife - and thus rush their enemies on command. They have reserves, and young, ignorant soldiers are less likely to rebel.
Armament: Staff weapons fire energy bolts which are loud, flashy, and inflict distinctive wounds, but are really hard to aim, rarely do damage beyond twenty meters and fire only once a second. People with decades of training such as Teal'c and Master Bra'tac can hit a human-sized target at range two times out of three. Fanon is that they are purposefully Awesome but Impractical - modified to produce louder, brighter bolts at the cost of range, accuracy and power.
O'Neil: This... (lifts a staff weapon) is a weapon of terror. It's made to... intimidate the enemy. (throws staff weapon away) This (lifts the P90) is a weapon of war. It is made to kill your enemy.
Once the marines wind up at a rebel training camp, they give them FN-P90s and decent training. It's the birth of the Free Jaffa Nation!
O'Neil outright stated that their armor and weapons were designed for intimidation, not killing. The Ori solders, who use simpler weapons that were designed for killing and ease of use, are so much deadlier despite being mostly untrained peasants, though still blindly fanatical mooks that die by the hundreds.
The sheriff's men from Robin of Sherwood. The Merry Men of Sherwood killed ten or so per episode. It really got to the point where you had to wonder what kind of recruitment package was being offered.
Most of the villains in Firefly have gangs of hired goons, mercenaries, or thugs to back them up. In particular, Rance Burgess and Adelei Niska seem to have their own personal armies.
In The Sixties spy series The Man From UNCLE, THRUSH employs metric tons of Mooks. They even wear uniforms and have distinct ranks of officers (whether commissioned or non-commissioned is left up in the air) and other ranks, usually distinguished by their uniforms when both types appear.
Subverted by Heroes, volume 4: when a Mook is sacrificed by Danko to keep his plans moving, Nathan tells him about the Mook's wife and children.
In 'Once More With Feeling,' they were also trained dancers.
Buffy calls the mercenary demon from the episode "Flooded" a mook when he breaks her designer lamp.
The named warriors of Season 3 of Deadliest Warrior are always accompanied by four Mooks, who never survive the sim. Jesse James vs. Al Capone of Season 2 also had three mooks each, though it's subverted by there being another survivor alongside Jesse James, who's often speculated to be Jesse's big brother Frank..
An early 1990s SNL sketch shows footage from an action movie of a hero beating up a group of ninjas. Afterwards they try to evaluate what went wrong:
Ninja Leader: Okay, guys, pointing fingers won't solve anything. Now, if we want to get out of this rut.. we have to learn from these little disasters. Now, before the fight, how did we all agree we should attack the guy? Group: All together! Ninja Leader: And how did we attack? Group: One at a time..