Tony Stark’s Iron Man armors have become a titan in the MCU. But from the Mark I to his Iron Legion, there are many secrets fans still don’t know.

In his 15 years operating in the Marvel Cinematic Universe, Tony Stark developed quite an elaborate collection of armor. What started as a means of survival has since become a chance to push the limits of technology and, most importantly, the ability to save lives.

While many of his most iconic suits are instantly recognizable to long-time fans of the franchise and casual fans alike, there remains a variety of secret one-offs and hidden features that some fans might not know about Iron Man’s MCU armory. From its variations to hidden weapons, here are just some things you ought to know about the Armored Avenger’s cinematic suits and gadgets.

There Are 85 Different Iron Man Armors in the Marvel Cinematic Universe

Iron Man first appeared in 2008’s Iron Man.

While many audiences understand that Tony has a large collection of armor, some might not understand just how expansive that collection stretches. The pure scope of his MCU armory was first explored blatantly in Iron Man 3 when Tony initiated the ‘House Party Protocol’ that sent countless suits of armor to Tony’s location to save him and Pepper from the grip of Aldrich Killian. Although many of these suits were destroyed in the wake of the battle — and Tony’s climactic decision to destroy what remained — more and more suits were crafted throughout the rest of Phases II and III of the MCU.

By the time Tony made the ultimate sacrifice in Avengers: Endgame, a total of 85 Iron Man armors existed in the MCU, not including the Iron Legion robots, Pepper Potts’ Rescue suit or the War Machine armors Tony made for Rhodey. While this pales in comparison to the countless amount of suits owned by the 616 Marvel Comics versions of the character, this is still a staggering number, especially considering all of these suits appeared within just over a decade of MCU appearances. And although they aren’t all Tony’s suits, the number of Iron Man-adjacent suits in the MCU will only grow in future appearances of Riri Williams in Ironheart and James Rhodes in Armor Wars.

The Mark IV’s Advanced Drinkable Urine Filtration System Let Tony Urinate in His Suit… And Drink What’s Left

The Mark IV first appeared in Iron Man 2.

In one of the most embarrassing moments of his career, Tony hosted a party in his Malibu mansion while drunkenly donning his Mark IV armor. After being confronted by his then-assistant, Pepper Potts, Tony remarked that she needn’t worry about him drinking so much, as the Mark IV featured an Advanced Drinkable Urine Filtration System, implying that he could not only urinate in the suit, but that said urine would be filtered into some sort of drinkable liquid. Pepper is understandably disgusted and quickly moves on from the altercation, but fans have long been puzzled by this claim.

Although some might brush this off as a joke, Tony is not above implementing minuscule features into his suits, even on the pretense of a joke. Besides, as someone who was, at the time, a raging alcoholic, this would be seen as a luxury he could very much take advantage of. Audiences might never have solid proof that this liquid device was a reality, but all signs point to this being an actual feature of one of the character’s most iconic suits.

The Mark III Has Hidden, Highly-Powered Miniguns

The Mark III is made of a gold-titanium alloy.

The Mark III is one of the most instantly recognizable MCU Iron Man suits, as it was the first cinematic suit to don the iconic red and yellow color scheme. In one of the first scenes in which Tony wears the suit, he takes it for a spin as he rescues innocent Gulmira victims from the terrorists of the Ten Rings. Many fans might be too caught up in the epic action of the scene to notice an extra cool gadget that this suit features: wrist gauntlet miniguns, with 6 shots available from each wrist.

While this isn’t the only suit in Tony’s armory to contain this feature, it was likely the first, assuming this was an addition that happened between Mark II and this one. What can be said for certain is that this is the suit that is most spotlighted with this capability, as Tony epically uses them to his advantage in this iconic action sequence. This cements Tony’s arsenal as more unique than the lasers and jet boosters he’s so frequently shown to have.

The Hulkbuster Armor Has a Companion Piece Named V.E.R.O.N.I.C.A.

The Hulkbuster armor is powered by multiple arc reactors.

The Hulkbuster was a fan-favorite armor when it was first introduced in the comics, so fans were hotly anticipating its debut in Avengers: Age of Ultron. Luckily, the lumbering armor lived up to its legend and delivered one of the most memorable sequences in an often-forgotten MCU entry. Although it was heavily featured in the Hulkbuster and Hulk’s clash, many fans tend to forget one of its coolest features.

While Tony gets the life beat out of him by the Hulk, the Hulkbuster’s companion piece, a drone named V.E.R.O.N.I.C.A., scans the damage and provides Tony with replacement parts made out of nearby debris. This is an incredibly unique feature that might only work in the specific context that the Hulkbuster is used in, but it is still odd that Tony never seemed to have implemented similar features into other suits. Regardless, it’s one of the coolest aspects of a suit already overflowing with cool factor.

The Mark XV Was the First Armor Given a Nickname By Tony

The Mark XV first appeared in Iron Man 3.

It would come as no surprise to Iron Man superfans that Tony Stark frequently nicknames his suits of armor, but what might come as a shock is that he didn’t verbalize his individualized vision of each suit until Iron Man 3. The very first suit to receive this honor was the Mark XV, whom Tony refers to as Stealthy. This name is fairly self-explanatory, given the suit’s stealth capabilities.

Unfortunately, Stealthy was one of the many casualties of the battle with Killian in Iron Man 3, but its legacy lives on. Future suits would borrow from its technologies, enabling Iron Man to adapt to more stealthy situations from Age of Ultron onward. Perhaps more potently, the suit marked the beginning of Tony’s nicknaming principles — at least in the realm of suits — and for that alone, it deserves to be remembered.

The Mark XX and Mark XXXI Have Superspeed Capabilities

The Mark XX and Mark XXXI both first appeared in Iron Man 3.

Iron Man might be most praised for his excellent use of weaponry and flight capabilities, but what some might fail to consider is just how fast he can fly. While almost every Iron Man suit is capable of flying large distances at incredible speeds, there are a select few that Tony engineered specifically to push the limits of speed. Most notably, the Mark XX and Mark XXXI armors were engineered to reconfigure energy reserves into usable jet boosts.

As cool as this feature might be in specific situations, it isn’t very practical. Tony likely decided there were much better avenues to channel this excess energy in future suits, choosing to abandon this prospect in future models. Still, these suits serve as reminders that Tony was always improving upon even the most barebones elements of his suits, which is an understated hallmark of his character.

The Mark XXXIV Has a Shockingly Practical Use

The Mark XXXIV first appeared in Iron Man 3.

Most of Iron Man’s endeavors were crime-fighting, “Avengers-level” threats, but Tony had always imagined the Iron Man persona as something larger than even that. Although it was rarely showcased on-screen, Tony always had his eyes out for ways to help street-level problems. One such response to this can be found in the Mark XXXIV armor, codenamed Southpaw.

The Southpaw armor was designed to combat natural disasters, but unfortunately, it was stuck in something of a prototype phase before its destruction in Iron Man 3. Given its prototype status and the fact that it is relegated to a few background appearances, it isn’t fully clear how these needs would be confronted, but it likely involves the suit’s namesake, a peculiarly built arm supposedly for protection from scattered debris. Regardless, it is a sweet memento in Tony’s armory as proof that his sights weren’t always on the likes of otherworldly threats and were instead sometimes rooted in the very planet he inhabited.

The Mark I’s Biggest Downfall — And Its Most Unique Factor

The Mark I was strictly a one-use suit.

The Mark I isn’t the most glamorous Iron Man armor by any stretch of the imagination, but it holds a place in many fans’ hearts as an endearing first step in Tony’s complicated journey. While many of the suit’s most iconic features wouldn’t be implemented until the next two versions of the armor, some of its biggest assets were here from the moment Tony and Ho Yinsen assembled it. Namely, the Mark I included the arc reactor, wrist gauntlet weapons, high durability, significantly weaker but still present jet boosters, and an early version of Iron Man’s iconic helmet.

Unfortunately, the suit weighed a staggering 90 pounds. On one hand, this makes it even more impressive that Tony was able to use it so successfully. But it’s also incredibly impractical, prompting the necessary revamps in future models of the suit. One of the coolest features this suit has that wouldn’t be featured on many other versions of the Iron Man armor were the flamethrowers. Understandably, Tony opted for missiles in future versions, but that doesn’t make the flamethrowing any less cool.

The First Iron Legion Has a Surprising Regulation

The Iron Legion drones became the first vessel for Ultron.

After the events of Iron Man 3 and a quickly reversed promise to not rely so heavily on technology, Tony began work on a militia of Iron Legion drones that he could dispense at will to protect citizens in places where he can’t be. While these drones were largely controlled by J.A.R.V.I.S.. But before that, the Iron Legion was an army of suits used by Tony to stop Aldrich Killian and the other Extremis soldiers.

For the majority of his first armory, Tony programmed the suits to exclusively allow him as a pilot, save for the Mark 42 being used by Pepper or Rhodey wearing Stark-designed War Machine suits. This is a shocking revelation that truly illuminates the distraught and tortured mindset Tony was in at this point in his life — the same level of anxiety that would prompt his invention of Ultron alongside Bruce Banner, right before things would famously go astray.

The Mark XXIX Is One of the Most Underutilized Suits in Iron Man’s Armory

The Mark XXIX first appeared in Iron Man 3.

Tony’s Southpaw armor wasn’t the only suit to have a mundane but useful secondary use. The Mark XXIX, codenamed Fiddler, had a practical use that was never fully utilized within the Marvel Cinematic Universe. Fiddler could, under the right circumstances, act as a necessary construction companion, utilizing advanced technology to be able to both navigate through construction sites and provide help with actual construction, largely using its attached pneumatic jackhammer.

While Tony didn’t get much use out of the suit before its destruction, he likely implemented some of its technology into future suits and pieces of Stark technology used to develop Avengers Tower and, later, the New Avengers Facility. This is just one of many suits that hint at alternate routes Tony’s brainpower and Iron Man technology could have gone if only his focus had pivoted. But something about construction sites doesn’t seem as cool or important as confronting the likes of Thanos, but such things are up to fan interpretation and theorizing.