The deal with color-changing mugs is that, when hot liquid is added, a new picture magically (OK, magic is relative) appears. While it's more fun to pretend that they're the product of Hogwarts-style magic, heat-sensitive mugs work through something called thermochromism. Heat-sensitive mugs are made with special paint that takes advantage of thermochromism by swapping shades based on low and high temperatures. Think of these mugs as adult mood rings that use body heat to read your emotional state. It's the same concept, more or less. 

Now, go forth and gift your buddy or bae the perfect color-changing mug based on his or her personality.

For the space nerd

Can you connect the dots (or the stars, rather)?
Heat Changing Constellation Mug, $13.95, Amazon.com

For the historian

You know what they say, "Life is better naked."
Great Nudes Heat Changing Coffee Mug, $14.95, Amazon.com

For the arcade lover

Don’t let the ghosts catch you.
Pac-Man Heat Change Mug, $14.46, 
Amazon.com

For the gamer

#winning
Paladone Tetris Heat Changing Mug, $5.50, Amazon.com

For the gamer who also loves anime

With hot coffee, you can become Super Saiyan Blue, too.
Dragon Ball Z Goku Super Saiyan Blue Color Changing Cup, $13.29, Amazon.com

For the Super Mario Bros. fan

You will defeat Bowser and save the princess.
Super Mario Bros. Heat Change Mug, $9.99, Thinkgeek.com

For the Harry Potter fan

Colovaria *whizzes wand around*
I Solemnly Swear...Mischief Managed Heat Transforming Mug, $17.95, Harrypottershop.com

For the Star Wars fan

May the force be with you.
Star Wars Death Star Heat Change Mug, $12.99, Thinkgeek.com

For the one who stole your heart

Lub dub, lub dub, lub dub.
Pixel Heart Heat Changing Mug, $11.99, Thinkgeek.com

For the chronically tired

Open your eyes, dude.
Wake-Up Cup Heat-Sensitive Color Changing Mug, $13.95, Amazon.com

For the friend who refutes evolution

“God creates dinosaurs. God destroys dinosaurs. God creates man. Man destroys God. Man creates dinosaurs.” —Ian Malcolm, Jurassic Park
Disappearing Dinosaur Mug, $13.95, Amazon.com

For the one who always needs a little recharge

Power up.
econoLED Battery Color Changing Thermometer Cup, $12.99, Amazon.com

For the IT guy at work who takes pity on you when the Wi-Fi is down

A cromulent substitution.
Fred & Friends HOTSPOT Heat-Sensitive Mug, $11.55, Amazon.com

For the climate change denier 

Give the skeptic a daily reminder of how much global warming SUCKS.
Climate Change Disappearing Coffee Mug, $14.95, Amazon.com

For the panda-obsessed

Unfortunately, it can’t give you cuddles but it does provide emotional support.
MyPartyShirt Panda Heat Changing Mug, $16.99, Sears.com

For the thalassophile

Dun, dun, dun, dun.
Shark! Heat Changing Coffee Mug, $13.95, Amazon.com

For the one with quick bowel movements

brb gotta go.
Nevermind I Have to Go Poop Now Heat Sensitive Mug, $16.99, Amazon.com