Inflatable costumes work because a small battery-powered fan keeps pushing air into a fabric suit faster than it leaks out. Elastic seals at the neck and cuffs help keep the air in. In the costumes below, the fan runs on 4 AA batteries, which are not included, and the two product pages that state a run time say over 4 hours, so pack spares for a long night.
We make inflatable costumes for kids and adults, and our inflatable costumes page splits them into an adult section and a kids section. Choosing a design is a separate job, covered in our best inflatable costumes guide, our best kids inflatable costumes guide, and our adult party guide. Here we stay with the fan and what keeps it running.
What are the parts of an inflatable costume?
Four parts do the work, and the Kids Black Megamorph has all four: a built-in fan, a battery pack that takes 4 AA batteries, elastic seals at the cuffs and neck, and a 100% polyester shell. A hidden pocket holds a phone. The table sets out what each part does and where our product pages say so.
| Part | What it does | What our product pages say |
|---|---|---|
| Fan | Pushes outside air into the suit | Built into the suit on the Black Megamorph, which inflates in seconds; on the Grim Reaper the costume stays puffed up while the fan is running |
| Battery pack | Powers the fan | Requires 4 AA batteries, not included; tuck the pack into the internal pocket before you switch the fan on |
| Elastic seals | Help keep the air in at the openings | Seals at the cuffs and neck on the Megamorph; on the Grim Reaper they keep the air in |
| Shell | Holds the shape | 100% polyester; the Grim Reaper page adds reinforced stitching and a secure fan housing |
| Keeps a phone reachable | A hidden pocket on the Megamorph, a built-in pocket on the Evil 3-Headed Dog |
Is an inflatable costume sealed like a balloon?
No, and that is why there is a fan. A balloon holds the air it was filled with, but a costume has openings at the neck and cuffs, so some air always escapes and the fan keeps replacing it. The seals help keep the air in; the fan, powered by 4 AA batteries, keeps the suit full for as long as it runs.
What are inflatable costumes made of?
The Megamorph, the Evil 3-Headed Dog, and the Grim Reaper are all 100% polyester, and the Megamorph and Evil 3-Headed Dog pages call it lightweight and durable. The Grim Reaper page adds reinforced stitching and a secure fan housing.
Every costume goes through over 30 measurement checks, and we run over 500,000 quality checks a year.
How long do the batteries last?
The Megamorph and the Evil 3-Headed Dog pages each say over 4 hours of battery life; the Grim Reaper page gives no run time. Load the batteries before you put the costume on: the Megamorph page says the pack must be loaded before wearing to reach full inflation, then tuck it into the internal pocket and switch the fan on.
None of the three costumes includes batteries, so buy a second set of 4 AA for a long evening. If a fan or pack needs replacing, the replacement battery pack and fan page lists an adult battery pack and fan that requires 4 AA batteries, also not included.
Are inflatable costumes hot to wear?
None of the Megamorph, Evil 3-Headed Dog, or Grim Reaper pages states a temperature, and we will not guess at one; a full-body costume holds some warmth. The American Academy of Pediatrics' extreme-heat guidance for children, updated June 30, 2026 and written for hot weather rather than costumes, says to come inside regularly to cool off, rest, and drink water. At a warm party, take the same kind of break: move somewhere cooler, drink some water, and rest before you go back in.
What should you know before you wear one?
The Megamorph page carries two warnings: keep the costume away from fire, and it is not suitable for children under 3 years because of small parts. The AAP's Halloween tips, written for children's costumes and updated September 29, 2026, say a costume should be short enough to prevent tripping.
An inflated shape adds bulk around you, so test the route before the event: walk to the door, the stairs, and the bathroom with the fan running.
What size do inflatable costumes fit?
Each of the three costumes below is listed as one size fits most, and each page points you to a size chart or size guide image. The Grim Reaper page gives the range: designed to fit most children from 3'11" to 5'3" (120 to 155 cm), worn over their own clothes. The adult inflatables we read for this guide are listed as one size fits most too.
Expect a looser fit over everyday clothes: our Kids Police Pick Me Up page says a looser fit is normal and expected.
How do you care for an inflatable costume?
Hand wash only, after you take out the battery pack and switch the fan off; the Evil 3-Headed Dog and Grim Reaper pages say the fan comes out too. The Megamorph page says do not machine wash or tumble dry, and the Grim Reaper page adds no iron or bleach. Let it air dry fully before it is inflated again or stored, then deflate it and keep it flat in a cool, dry place, away from sharp objects.
Which costumes show each design?
Between April 22 and October 14, 2026, about 7 in 100 of the orders recorded on our U.S. website included a costume with inflatable in its name. Three kids' designs show the three ways the idea works: an all-in-one suit, a ride-on, and a pick-me-up.
Kids Black Inflatable Megamorph: the all-in-one suit
The Kids Black Inflatable Megamorph builds the fan into the suit, so the fan is already part of it. The page says it inflates in seconds, with elastic seals at the cuffs and neck and a hidden pocket for a phone. One size fits most children, and the 4 AA batteries it needs are not included.
Kids Evil 3-Headed Dog Ride On Inflatable Costume: the ride-on
The Kids Evil 3-Headed Dog Ride On Inflatable Costume turns a child into a three-headed Cerberus. The pack holds the costume and a fan with a battery pack, which needs 4 AA batteries, not included. The page promises over 4 hours of battery life, elastic seals, and a built-in pocket.
Kids Pick Me Up Grim Reaper Inflatable Costume: the pick-me-up
The Kids Pick Me Up Grim Reaper Inflatable Costume looks as though the reaper is carrying your child away. Once your child is inside and the built-in fan is on, the page says it stays puffed up while the fan is running. It fits most children from 3'11" to 5'3" and takes 4 AA batteries, not included.
Frequently asked questions
How do inflatable costumes stay inflated?
A small fan keeps adding air faster than it escapes, and elastic seals at the openings slow the leak. The Grim Reaper page says the costume stays puffed up while the fan is running, so the fan stays on for the whole wear.
Do you keep the fan on in an inflatable costume?
Yes. The fan is what keeps the suit full, so it runs for as long as you wear the costume. Load 4 AA batteries before you put it on, as the Megamorph page advises, and carry a second set for a long night.
What batteries do inflatable costumes need?
The Megamorph, the Evil 3-Headed Dog, and the Grim Reaper each need 4 AA batteries, and none includes them. Our replacement battery pack and fan also requires 4 AA batteries, not included.
Is it hot inside an inflatable costume?
Our product pages state no temperature, and we will not guess at one. A full-body costume holds some warmth, and the American Academy of Pediatrics advises children to come inside regularly to cool off, rest, and drink water when they are out in the heat, so take a break somewhere cooler at a warm party.
Can you sit down in an inflatable costume?
Our product pages do not give a sitting guide, so try it at home with the fan running before the event. The costume is worn over everyday clothes and the air holds its shape, so leave extra room and pick a seat without arms.
What are inflatable costumes made of?
The three costumes on this page are made from 100% polyester. The Grim Reaper page also names reinforced stitching and a secure fan housing.
Can you wash an inflatable costume?
Wash it by hand, never in a machine or a tumble dryer, after you take out the battery pack and switch the fan off. Let it air dry fully, then deflate it and store it flat somewhere cool and dry.
