Heat changing mugs are incredibly cool, and the perfect way to celebrate the fandom that makes you geek out.

What are heat changing mugs?

The effect is a lot like those pens from the ’70s, the ones that displayed a perfectly normal woman, until you tipped the pen. Then her clothes would disappear. But, heat changing mugs aren’t R-rated. They start out as a black mug. Once hot liquid is poured into it, the mug reveals hidden pictures and words.

Unlike those naughty pens, however, the process that reveals the hidden pictures on the heating changing mugs is actually chemical. The black paint is a thermochromic dye that’s made from mixtures of leuco dyes and other suitable chemicals. As ScienceABC explains, “Such dyes usually come in the form of micro-capsules that have the mixture sealed inside them… The dye is mixed with salt crystals that are either very acidic (low pH) in nature or very basic (high pH), and the paint is sensitive to changes in the pH of the environment. Therefore, when the temperature changes, a chemical reaction takes place and those crystals mix with the dye… The optical properties of the dye change, making it appear either opaque or completely transparent! In short, it’s the melting of those crystals (that are already mixed with the dye) that changes the pH of the environment.”

Note: Do not put heat changing mugs in the dishwasher! The outer coat will deteriorate and the magic will disappear. (Trust me.)

Which heat changing mugs are the coolest?

Now that the technical mumbo jumbo is out of the way, let’s get to the important bit. I’m lucky enough to have a husband who bought me two (yes, two!) heat changing mugs. Of course, it only makes me want more! The two I have are Harry Potter heat changing mugs, which is perfect, because they reveal things just like magic! This is a video of my “I solemnly swear I am up to no good” heat changing mug. I also have one that reveals the Marauder’s Map.



There are plenty of geek heat changing mugs available. The ones I’ve pulled together here, however, are my favorite ones.

Disclaimer: If you click any of the links below and make a purchase, Media Medusa receives a small commission. Thank you for your support.


Avengers Civil War Heat Changing Mug

The Captain America: Civil War heat changing mug reveals the big battle between Team Iron Man and Team Cap. The image looks more like concept art than photos of the actors, which I happen to prefer.

Avengers Captain America Heat Changing Mug

This slick Avengers Captain America heat changing mug is very minimalist. Cap’ is taken from the comic books, along with his iconic shield. Great for die-hard fans!

Doctor Strange Heat Changing Mug

Just in time for the new Doctor Strange movie in November, this (kinda creepy) Doctor Strange heat changing mug shows the Eye of Agamotto Amulet when you pour in hot coffee or tea.

Guardians of the Galaxy Heat Changing Mug

This Guardians of the Galaxy heat changing mug is super cute! The characters are more cartoon than comic book. Pouring hot liquid into the mug reveals Groot giving Rocket Raccoon a scare.

Marvel Villains Heat Changing Mug

This super Marvel villains heat changing mug reveals a few of the Avengers’ worst foes, including Red Skull and Loki.

Harry Potter

Dobby Heat Changing Mug

Alas, poor Dobby! This is a sweet Dobby heat changing mug that reveals our favorite house elf, against an aquamarine and gold background.

Fantastic Beasts Friends Heat Changing Mug

In time for the new movie in November, this Fantastic Beasts cast photo heat changing mug reveals Newt Scamander, Porpentina Goldstein, Queenie Goldstein and Jacob Kowalski.

Fantastic Beasts Symbol Heat Changing Mug

The other Fantastic Beasts heat changing mug reveals a mysterious symbol, of which I’m looking forward to an explanation. Zodiac symbols? Surely not.

Slytherin Heat Changing Mug

Leave it to a Slytherin heat changing mug to disguise itself as an innocent cup, only to reveal its true nature! The Harry Potter online store also has heat changing mugs for the other Hogwarts houses, in case you weren’t sorted into Salazar’s house.

Snape Always Heat Changing Mug

When Snape showed Dumbledore his Patronus, it was still a doe. She represented Lily Potter, whom he had loved. When Dumbledore asked, “Still?” Snape replied, “Always.” That quote took on special meaning earlier this year, when Alan Rickman, who played Snape, died in January. Many fans took the quote to heart. This “Always” heat changing mug, then, is especially meaningful.

Snape Heat Changing Mug

This Snape heat changing mug reveals images of the potions professor at his finest. Or worst, depending on your viewpoint. The Harry Potter shop has several other heat changing mugs that feature other characters and cast members.


Arkham Joker Heat Changing Mug

The Batman Arkham video game series is incredibly popular. This Arkham Joker heat changing mug reveals the ghoulish grin of Batman’s sneakiest foe.

Wonder Woman Heat Changing Mug

Wonder Woman was arguably the best part of Batman v Superman: Dawn of Justice. She stole the final battle scene away from the boys. This Wonder Woman heat changing mug celebrates her warrior spirit.

Dark Knight Bats Heat Changing MugFans of Chris Nolan’s version of Batman will like this The Dark Knight Trilogy heat changing mug that reveals Christian Bale and a lot of bats.

DC Sleigh Heat Changing Mug

You know that Jingle Bells parody about Batman smells? This “Sleigh the Batman” heat changing mug doesn’t show Robin laying an egg, but it’s perfect for the holidays.

Arkham Harley Quinn Heat Changing Mug

This Arkham Harley Quinn heat changing mug is only one of several on this list that feature the Joker’s wacko girlfriend. The Arkham version is one of my favorites, though, with Harley’s punk look.

Bombshell Harley Quinn Heat Changing Mug

The DC Bombshells series shows a variety of DC women — superheroes and villains — in ’40s pin-up style. This Bombshell Harley Quinn heat changing mug shows Harley looking almost innocent. Almost.

Dark Knight Joker Heat Changing Mug

Why so serious? For many Batman fans, Heath Ledger was the ultimate Joker. This The Dark Knight Joker heat changing mug reveals Ledger’s creepy Joker, and his laughter.

Justice League Heat Changing Mug

All the members of the Justice League will be coming together for the new DC movie in 2017. In the meantime this Justice League heat changing mug reveals all the major players.

DC Naughty List

Here’s another DC heat changing mug that would go great with some hot cocoa and marshmallows. Looks like these lil’ DC characters got put on Santa’s naughty list.

Suicide Squad Heat Changing Mug

We can’t leave out this Suicide Squad heat changing mug. These “worst heroes ever” took in over $318 million at the box office, putting it in the top 10 movies for 2016 (to date).

Both the Warner Bros. official store and Entertainment Earth have even more (yes, more!) DC-themed heat changing mugs.


Beauty and the Beast Thomas Kinkade Heat Changing Mug

Combining the art of Disney with the style of Thomas Kinkade is like a sugar overload. However, I love it! Those blurry pastels! The soft glow! This Beauty and the Beast heat changing mug shows Belle and the Beast falling in love.

Cinderella Thomas Kinkade Heat Changing Mug

Here’s another classic Disney scene. The Cinderella Thomas Kinkade heat changing mug reveals the princess in her brilliant blue gown, with the iconic castle in the background.

Little Mermaid Heat Changing Mug

Okay, last one, I swear. This Little Mermaid heat changing mug has all the great characters, the castle, AND a rainbow! Entertainment Earth has plenty more Disney heat changing mugs to choose from.

Star Wars

Star Wars Rebel Heat Changing Mug

Let this Star Wars heat changing mug show off your rebel alliance. (Yoda quote inside!)

Wizard of Oz

Good Witch Bad Witch Heat Changing Mug

It doesn’t matter if you’re a good witch, or a bad witch, because this Wizard of Oz Witch heat changing mug has you covered both ways.

Wizard of Oz Shoes Heat Changing Mug

This Wizard of Oz heat changing mug shows the famous ruby slippers, along with the slogan “Shoes to Die For.” Indeed, they were!

Tin Man Heat Changing Mug

So what if Dorothy wasn’t going to miss him most of all? His heart could take it! This cool Tin Man heat changing mug reveals, maybe, your favorite character. There are other Wizard of Oz character heat changing mugs at Entertainment Earth.

Lord of the Rings

Lord of the Rings Mordor Heat Changing Mug

Nothing goes together better than heat and Mordor. This Lord of the Rings: Return of the King heat changing mug reveals the silhouettes of our heroes against a fiery Mordor sky.

Lord of the Rings Heat Changing Mug

I love the collage that’s revealed on this Lord of the Rings heat changing mug. There are plenty of other Hobbit and Ring-themed heat changing mugs at Entertainment Earth.

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31+ Heat Changing Mugs