It's a long-running war series from Battle Picture Weekly, starring a bunch of unrepentant scumbag criminals who hate their commander. It's basically a British WWII equivalent of DC's Suicide Squad, but with no superpowers and a far higher body count. It's pretty cool, actually. I don't know if it's necessarily a better series than, say, Major Eazy or Darkie's Mob, but it's probably more accessible for a modern comics reader. Its episodes are six pages long (and would sometimes later reach eight pages), rather than just three or three-and-a-half. John Wagner and Pat Mills were deliberately reinventing the concept of British boys' comics, which were in a slump at the time, and there's a reason why this feels more modern than most of what was around back then.
Also, importantly, the Rat Pack really are irredeemable dirtbags who are perfectly capable of trying to murder their commander (or each other). There's way more characterisation in a Rat Pack episode than there is in most war comics, because our anti-heroes hate each other and might go off-mission at any time. There are five of them:
1. MAJOR TAGGART, i.e. the Amanda Waller figure, except that he goes on missions too. If he didn't, no one would never come back. He broke them out of prison and is constantly threatening to send them back. The only reason they haven't killed him yet is that he's cleverer than any of them and is also a tough-as-nails stone cold bastard. "That's why convicts were chosen. Your deaths would be no loss to anyone!"
2. KABUL HASAN, a thuggish muscleman who talks in Hulk-speak. "Pah! Turk not need weapons!" "You are a smart man, Taggart! When time comes for Turk to kill you, I be very careful!" He's a lot of fun and the most entertaining character in the early episodes, but later on he'll fade into the background. He's just a gorilla. He's incredibly violent, prone to fits of rage and absolutely not someone you'd want in the same room as you, but he's also more straightforward than the other rats. Give him some skulls to shatter and he'll be happy.
3. RONALD WEASEL, of the oh-so-subtle name. He's a lockpicker, thief and dirty snivelling coward. He has an important role in the team, but he'll also sell out his friends and avoid combat whenever possible. In one episode, he'll try to murder Dancer by booby-trapping his rifle. "H-hello, I dropped me gun. I was looking for it!"
4. IAN "SCARFACE" ROGAN. The blandest rat. He's a superb athlete, but beyond that his characterisation is mostly just "Scottish". That said, though, there's an episode here where he double-crosses everyone to try to murder the man they've been sent to rescue.
5. MATTHEW DANCER. The scariest rat. He's an elegant, posh-looking man with a pencil moustache and probably Brylcreemed hair. He also takes pleasure in killing and really likes knives. At one point, he ignores Taggart's orders to stop fighting because he's enjoying the kills too much. He's the most untrustworthy rat (which is saying a lot) and he's often keen to murder people they've been sent to rescue, since transporting them alive is too much effort. He'll say things like:
"I say we leave Taggart here to freeze to death in the snow."
"No, Dancer. When Taggart dies, it will be Turk who kill him and he must know it was me. Let us be on our way."
Then there's the episode where Weasel's pretending to be hurt in an ambulance:
"B-blimey - they'll see I ain't injured."
"Don't worry, Weasel... I can do something about that..."
"'Ere, Dancer, your eyes 'ave gone all funny... just like when you're killing... no! no! please!"
The missions tend to be dirty. They might, for instance, be asked to either rescue or kill a resistance commander who's fallen into Gestapo hands and is being tortured. On one mission, they rob Hermann Goering. Unfortunately there's a problem with asking the rats to steal valuables, which is that this gives Taggart a two-part headache. #1: steal gold from Germans. #2: protect gold from rats.
I'm not reviewing all of it here, by the way, but just what got reprinted in Titan's 2012 graphic collection.
I'd love to see the Rats return... and apparently they have! They guest-starred in a 2018 mini-series, Sniper Elite: Resistance, a bit like Garth Ennis in 2015 writing a new mini-series for the Battle Picture Weekly character, Johnny Red. There's a lot of character and scary evil bastard behaviour in these six-page episodes. You wouldn't need to update anything to bring this lot back. They could step straight into pretty much any modern comics exactly as they are. Their Major Eazy crossover came to pass, for instance, when they got Taggart hospitalised by deliberately abandoning him to the Gestapo.
They're cool. Absolutely ghastly people, obviously, but still cool. I'm not saying that out of retro irony, but in all seriousness.