Are you a Sulley's biggest fan? Then you need this awesome Sulley mask that mimics your own facial movements when worn! The moving mask is designed to fit most kids but many reviewers indicate it works for adults just as well!

This officially licensed costume from Disney/Pixar will transform your little one into legendary scarer Mike Wazowski. The outfit is a jumpsuit with foam Mike W. overlay. This toddler costume comes with Monsters University baseball cap.

You can be just like old Sulley here with this officially licensed jumpsuit! But don't be surprised if you're not considered scary, because we're with Boo on this one... he's big, fuzzy, and spotted with purple. As Boo would say, he's just a big "kitty."

This Mike Wazowski baby costume includes a printed foam flannel jumpsuit with character overlay, Monsters University baby cap, and matching green booties. This is great for fans of Monsters, Inc. and the exuberant Mike W!

This adult costume onesie jumper is perfect for Halloween -- or casually lounging around at home!  You can "scare" the neighborhood when you go out trick-or-treating this year with this adorable costume of James P. Sullivan. The hooded jumpsuit pajama-style costume comes with a tail on the back and doesn't include feet for maximum indoor / outdoor versatility.

Not ready for a whole costume but still a huge fan of the famous Monsters? Then check out this adorable green Mike Wazowski sunglasses costume accessory. You will scare anyone that you will lay your EYE on! The glasses include a large Monster eye above your own shaded eyes.

Part mask, part sunglasses, this awesome pair of Sulley Monster sunglasses is a great accessory for a complete costume, or a fun way to dress up without going too crazy.

Even if you weren't born with the scary good looks of Mike Wazowski, you can still be pretty monstrous wearing this cool Mike Wazowski costume for adults. It's the closest you'll get to being a real live monster.

This infant Sulley costume includes jumpsuit, detachable tail, headpiece and pair of booties. This is an officially licensed Disney Pixar product.

Dress up like the human child heroine of Monsters, Inc, little miss Boo! Boo wears a monster costume in the movie, looking a lot like this one! It's a fun one and great as part of a group or family costume idea.

Carry one or two of these cute plush donkey toys as the perfect accessory for your Luisa costume. While Luisa sings her signature song, Surface Pressure, she moves several of the beasts as part of her duties.

This one is easy! Bruno's main costume piece is the green striped poncho he wears, including a hood just like this one. Because this is the main part of his costume, you can wear this over almost anything, but brown pants and a brown top would be best. It also works over jeans, shorts, or almost anything else! The poncho is king for a Bruno costume.

Go full-on rainbow with this rainbow mini dress! The dress is sleeveless on one side and extends the rainbow flag across the other arm.

Here's another way to go full-on rainbow. This is a tunic-style top where the width of the flag is the same on both sides.

Add some color to your legs with these fun fashion furry leg warmers. The long polyester fur has a vibrant rainbow color scheme.

These costume wings are made from real feathers died in rainbow colors. These are easy to wear with attached elastic straps so you can pair them with nearly anything.

Colorful horizontal stripes repeat over these oversized polyester knee socks.

Disappear into a rainbow with this form-fitting skin suit! The polyester outfit covers you from head to toe in rainbow colors.

This is a slinky dress in a flapper style with layered fringe. The dress is mostly red above with rainbow coloring on the skirt to the hem. The flapper dress comes with a matching red headpiece.

Pick up this organza rainbow tutu to wear on Pride Day! The lightweight article can go over almost anything and will add more than a touch of color!

Add a touch of drama to your Pride Day outfit with this long and flashy rainbow cape! You can pair this with almost anything and it's practical too -- keeping you warm in colder climates or keeping you out of the sun where needed!

Go rainbow above with this fun accessory! It's a cowboy or cowgirl style hat with a totally rainbow color scheme.