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Transformers Boy's Converting Optimus Prime Costume

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     Read Reviews (28)
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Item # DI104939
Items Included
  • Jumpsuit
  • Truck Cab
  • Pair of Wrist Cuffs With Attached Tires
  • Pair of Gloves
  • Pair of Boot Covers With Attached Tires
  • Mask
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Product Information

Size Chart
Runs Small
Slightly Small
True To Size
Slightly Large
Runs Large
Size Measurement Standard Metric
3T/4T Chest 23" 58cm
3T/4T Sleeve Length 16" 41cm
3T/4T Torso 23" 58cm
3T/4T Inseam 17" 43cm
Size Measurement Standard Metric
Size 4/6 Chest 28" 71cm
Size 4/6 Sleeve Length 17" 43cm
Size 4/6 Torso 24" 61cm
Size 4/6 Inseam 19" 48cm
Size Measurement Standard Metric
Size 7/8 Chest 30" 76cm
Size 7/8 Sleeve Length 19 1/2" 50cm
Size 7/8 Torso 25" 64cm
Size 7/8 Inseam 21" 53cm
Size Measurement Standard Metric
Size 10/12 Chest 33" 84cm
Size 10/12 Sleeve Length 22 1/2" 57cm
Size 10/12 Torso 28" 71cm
Size 10/12 Inseam 26" 66cm
Features
  • Fabric: 100% polyester; mesh: 86% polyester, 14% spandex; foam: 100% polyurethane
  • Jersey knit jumpsuit has hook and loop fastener at center back
  • All over printed graphics
  • Foam wrist cuffs slide on, have elastic band in upper edge
  • Wrist length gloves slide on
  • Foam boot covers have elastic band in upper edge
  • Molded plastic mask has elastic band around back of head, mesh covered eye openings for limited vision
  • Foam truck cab has mesh covered windshield for truck mode, head hole in top for robot mode
  • Illustrated transformation instructions are printed on item package
  • Officially licensed

The Outfit With a Truck Hiding Inside

Is he a robot? Is he a truck? Is he somehow both at the same time? With this Boy’s Transformers Converting Optimus Prime Costume, your kid becomes the ultimate playground legend. This is no ordinary robot costume—it actually coverts. One minute he's a towering Autobot leader. The next? Full semi-truck mode on the sidewalk, blocking imaginary traffic and collecting imaginary tolls.

It’s the kind of costume that makes every other kid say, “Wait—your costume turns into a truck?!” And just like that, your little hero becomes the most powerful force in the neighborhood (with the aerodynamics of a foam rectangle).

Product Details

This officially licensed costume comes with a printed jumpsuit covered in detailed Optimus Prime graphics, closing with a hook-and-loop fastener at the back. Foam wrist cuffs and boot covers feature attached tires and slide on over shoes with an elastic band. For a snugger fit, have your kid wear their usual sneakers underneath. The gloves and molded plastic mask finish the look, with mesh-covered eye openings that limit peripheral vision, so keep an eye on your trick-or-treater when they're in full mask mode.

The real showstopper is the foam truck cab. Your child stands inside it, head through the roof, then crouches down for full truck mode, complete with a mesh "windshield." It's designed as a one-size-fits-most piece that sits over the shoulders rather than scaling with costume size, so it can run roomy even at the right jumpsuit size. Avoid packing it tightly in storage between wears to help it hold its shape.

Transform, Trick-or-Treat, Repeat

This Converting Optimus Prime costume is the ultimate fusion of dress-up and toy magic. No batteries. No apps. Just a jumpsuit, a mask, and a foam truck cab your kid can drop into and out of on their own, robot one minute, semi-truck the next, over and over all night long. Pure, glorious conversion powered by your child. Autobots? Roll out!

Questions & Answers

Q: How is it packaged.. Will it fit in my suitcase.. Is it soft What is the size when it's packed (1 Answer)
Asked by JOAN | January 11, 2026
Monster Responds...
The jumpsuit is 100% polyester jersey knit, so it's soft and flexible, and the gloves are soft as well. The foam pieces, including the truck cab, wrist cuffs, and boot covers, are rigid urethane foam, so those will take up the most space when packing. We don't have a packed box dimension to share, but the foam truck cab is the bulkiest piece and is the main thing to plan around if suitcase space is tight.
(AI Generated Answer)

Q: Does the boot covers with tires change sizes from the 3t/4t to the 4/6 size or would they be the same size? (1 Answer)
Asked by Anonymous | October 16, 2025
Monster Responds...
The boot covers do scale with the size, so the 4/6 boot covers will be larger than the 3T/4T ones. Since the boot covers have an elastic band at the upper edge, they're designed to fit a range of leg sizes within each size group, and comparing your child's measurements to our size chart is the best way to land on the right fit.
(AI Generated Answer)

Q: Is the mask the same size on the 3T/4T as the next size up 4/6? (1 Answer)
Asked by Anonymous | October 4, 2025
Monster Responds...
The mask dimensions aren't broken out separately by size in our information, so we can't confirm whether it's identical across sizes. What we do know is that the mask has an elastic band around the back of the head, which gives it some flexibility in fit.
(AI Generated Answer)

Q: Does the costume come with the mask and gloves? Or are they sold separately? (1 Answer)
Asked by babyk | September 9, 2025
Monster Responds...
Both are included! The mask and a pair of gloves come with the costume, along with the jumpsuit, truck cab, wrist cuffs, and boot covers. Everything ships together as one complete set.
(AI Generated Answer)

Q: Can you tell me what the straps are for on the truck cab and HOW to use them? The can part is HUGE and keeps falling off him (1 Answer)
Asked by Marythemom | September 21, 2024
Monster Responds...
The step-by-step transformation instructions are actually printed right on the costume's packaging, so that's your best guide for exactly how the straps work and where they attach to keep the truck cab secure. The package walks through the full robot-to-truck conversion, which is where those strap details will be spelled out clearly.
(AI Generated Answer)

Q: Which size will go for a 6 yo boy? He is just an average boy, not big not small. (1 Answer)
Asked by Anonymous | June 5, 2024
Monster Responds...
Hey, if you look at our size chart we have dimensions for all of our sizes. If you would like to get the best fit we recommend to measure your child first and find the size that fits them best. It also looks like this costume could run slightly large so you could go up one size just in case.

Q: Does anyone know what the 2 clear plastic straws are for? (1 Answer)
Asked by amber | October 17, 2023
Monster Responds...
The costume's includes list covers a jumpsuit, truck cab, wrist cuffs with attached tires, gloves, boot covers with attached tires, and a mask, but no clear plastic straws are mentioned as part of this costume. If you found two clear straws in the package, they may be structural supports tucked inside one of the foam pieces, like the truck cab or wrist cuffs, to help them hold their shape. Check the transformation instructions printed on the package, since those walk you through assembling the costume into both robot and truck mode and may show exactly where those pieces go.
(AI Generated Answer)

Q: Can you please share the instructions to set up the costume? I cant figure out where the black stripes attach to. thank you so much! (1 Answer)
Asked by Carocord | October 13, 2023
Monster Responds...
The full transformation instructions are printed right on the item's packaging, so that's your best guide for the step-by-step setup. What I can tell you is that the costume includes wrist cuffs and boot covers that each have tires attached, so the tires are already part of those pieces rather than separate strips you need to connect.
(AI Generated Answer)

Q: Does this costume come in a size 14? (1 Answer)
Asked by Boy mom | October 8, 2023
Monster Responds...
The largest size we carry for this costume is Size 10/12, which has a 33" chest, 22.5" sleeve length, 28" torso, and 26" inseam. If your child's measurements are close to those numbers, comparing them against our size chart is the best way to find the right fit.
(AI Generated Answer)

Q: How in the world does the cab attach for this costume? Ours did not include instructions. (1 Answer)
Asked by Megan | October 8, 2023
Monster Responds...
The full transformation instructions are printed right on the item's packaging, so hang onto that box! For the cab itself, the foam truck cab has a head hole in the top for robot mode, and a mesh covered windshield for truck mode, so it's designed to sit over the head and shoulders to switch between the two looks.
(AI Generated Answer)

Q: Does this come in adult sizes????? (1 Answer)
Asked by David | August 2, 2022
Monster Responds...
Of course grown ups want to be able to transform, too! You can find the adult Optimus Prime converting costume under item number DI104939.

Reviews

4.2
     
5 Stars
54%
4 Stars
29%
3 Stars
11%
2 Stars
4%
1 Stars
4%
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Customers Say
Customers are generally very positive about this costume, with kids loving the look and fit of the main bodysuit. However, a recurring complaint is that the truck/car conversion piece runs extremely large and lacks sturdiness, often appearing floppy or collapsing, regardless of the costume size ordered. Some buyers also noted issues with ill-fitting boot covers and the occasional missing or damaged accessory.
(AI Generated Review Summary)
Transformers Boy's Converting Optimus Prime Costume
HalloweenCostumes.com Monster