Baby Animal Costumes and Hooded Rompers: Fabric, Sizing and the Rules That Matter

Solis Fortune Editorial · 11 min read · Ships to the US, Australia, the UK and the EU

What counts as a baby animal costume?

Two kinds of garment share the name. The first is the animal romper: an ordinary one-piece — sleeves, legs, a zip or buttons — with a character hood sewn on. It is loungewear that happens to be a dinosaur. The second is the photo costume: a shape built for the picture, like a five-point star or an octopus with arms that spread across a rug, where the costume is the point and the clothing is secondary.

The difference matters because it decides how often it comes out. A romper gets worn on cold weekend mornings, to the shops and at a birthday party. A photo costume gets worn for twenty minutes and a camera roll.

Which fabric should you choose?

Fabric decides warmth, feel and how the costume survives the washing machine. The five you will meet most often:

Heavier fabric is not automatically better. A thick fleece suit is exactly right for a walk in November and exactly wrong in a heated living room. If the costume will spend most of its life indoors, flannel or velvet is easier to live with.

How do you size an animal costume?

By height, not age. Two babies of the same age can be a size apart, and a size label in months is only a guess at how long a child is. Measure your child standing (or lying, for a baby) and match that to the height on the size chart.

• Between two sizes, go up. A costume is worn over a vest or a bodysuit, and a hood needs room for a growing head.
• Check the chest, not just the length, if the chart gives it. A romper that fits in length but pulls across the chest will not zip comfortably.
• For older children, the chart often runs 100 cm upward rather than in years. A child 115 cm tall takes the 120.

As examples from our own range: the Critter Onesie runs from a 70 (for heights 56–66 cm) to a 120 (100–110 cm); the Critter Onesie Kids runs 100 to 140 cm; the Shell turtle onesie goes from 0–6 months all the way to a one-size adult for 160–190 cm, which is what makes a matching family photo possible.

Zip or buttons?

Every nappy change happens through the closure, so it deserves more thought than it usually gets.

• A front zip is the fastest: open, change, close. The best ones run from the chin to the feet, so the whole suit opens like a coat. Look for a chin guard or a covered zip pull at the top so metal does not sit against the skin.
• Buttons down the front are slower but gentler, and they suit soft fuzzy fabrics that would snag in a zip.
• Shoulder openings, as on a crochet star suit, let the whole garment lie flat so you lay the baby onto it rather than threading limbs through sleeves.

Whatever the closure, check it before every wear. A loose button is a choking hazard at this age, and a zip pull that has worked free should be replaced before the costume goes back on.

Hoods, faces and safety

The hood carries the character, and it is also the part to watch. It should sit back on the head, never slide over the eyes or face, and it should stay clear of the nose and mouth when a baby is lying down. Stitched-on details — ears, horns, eyes, fins — are part of the costume; anything that starts to come loose should be sewn back before it is worn again.

Two costumes in the range are built for supervised floor play rather than wear on the move: the Octo Costume, whose arms spread 120 cm across a rug, and the crochet Star Suit. Both are for an awake baby with a grown-up next to them.

Can a baby sleep in an animal costume?

No. This is the part of the guide that is not a matter of taste, and there are two separate reasons.

The legal reason

In the United States, garments sold as children's sleepwear are held to dedicated flammability standards: 16 CFR Part 1615 for sizes up to 6X and 16 CFR Part 1616 for sizes 7 through 14. Both define sleepwear as clothing "intended to be worn primarily for sleeping or activities related to sleeping", and both exempt garments that are tight-fitting as the regulation defines it. A loose, hooded, plush costume is the opposite of tight-fitting — which is why every costume in our Baby collection is sold as dress-up and loungewear, and says plainly that it is not sleepwear.

The practical reason

The US National Institute of Child Health and Human Development's Safe to Sleep campaign and the American Academy of Pediatrics give guidance that applies directly to costumes:

• Keep the head and face uncovered during sleep. A hood is a head covering.
• Avoid overheating. The AAP notes that overheating can increase the risk of SIDS, and that a baby needs only one more layer than you would wear in the same room. A thick fleece or plush suit is several layers at once.
• Keep the sleep space bare — nothing in it but a fitted sheet. For warmth at night, both point to a wearable blanket or an extra layer of ordinary clothing.

The working routine: costume on for play, photos, parties and the walk home; costume off, and close-fitting sleepwear on, before a nap or bedtime. Watch for signs of getting hot — damp hair, flushed skin, a sweaty neck — and unzip early rather than late.

Photo costume or everyday romper?

If it will be worn every week, choose a romper with a zip in flannel, fleece or velvet. If it is for one set of pictures, a shape costume is the one that gets the shot. For a holiday photo, the Critter Onesie's reindeer, snowman and Santa designs and the Shell onesie's adult size cover the whole family.

The everyday rompers

Solis Critter Onesie — Blue Dragon Flannel hooded animal romper with a front zip — one of 38 designs, sizes for heights 56 to 110 cm. $44.99 — view product → Solis Critter Onesie Kids — Penguin Thick flannel hooded animal jumpsuit for children 100 to 140 cm tall — one of 43 animal designs in the Baby collection. $44.99 — view product → Solis Dino Hoodie Romper Thick fleece dinosaur romper with spines, a tail and a zip front — 6 months to 5 years, four colours. $44.99 — view product → Solis Bear Cub Romper Fuzzy footed romper with a button front and a matching bear-ear bonnet — 3 months to 3 years. $44.99 — view product → Solis Shark Suit Velvet shark jumpsuit with a 3D hood, fin and tail and a chin-to-feet zip — 3 months to 4T. $44.99 — view product → Solis Shell Turtle Onesie Plush turtle onesie with a padded 3D shell, fleece lining and a full-length zip — 0–6 months to adult. $44.99 — view product →

The photo costumes

Solis Octo Costume Hooded plush octopus photo costume, 120 cm arm tip to arm tip — pink or blue, ages 0–3. $44.99 — view product → Solis Star Suit Hand-crocheted hooded five-point star that opens flat — the photo outfit for the first two years. $44.99 — view product →

How do you wash an animal costume?

• Close every zip and fastening, then turn it inside out. It protects the pile and keeps a zip from catching the fabric.
• Machine wash cold for flannel, fleece, velvet and plush — the Shark Suit and Shell onesie care instructions both say machine wash cold and tumble dry low.
• Hand wash crochet and dry it flat. Hanging a wet crochet piece stretches it out of shape.
• Follow the sewn-in care label first. Where a supplier does not publish full fibre content, the label on the garment is the authority.

The whole range is in the Baby collection. For more on sizing a family in matching plush, read the turtle onesie guide; for the crochet star, the star suit guide.

Every Critter design

Critter Onesie (heights 56–110 cm), 38 designs: Blue Dragon, Orange Dragon, Little Monster, Fox, Snowman, Santa, Dino Print, Leopard, Wolf, Grey Cat, Blue Shark, Yellow Calf, Green T-Rex, Reindeer, Smiling Tiger, Penguin, Cow, Fox Cub, Pink Pig, Lion, Brown Monkey, Squirrel, Green Dino, White Unicorn, Grey Koala, Zebra, Elephant, Purple Bat, Grey Mastiff, Pink Kangaroo, Blue Groundhog, Brown Bear, Husky, Green Foal, Hedgehog, Pink Cat, Blue Hamster, Pink & White Cat.

Critter Onesie Kids (100–140 cm), 43 designs: Bat, Fox, Giraffe, Kangaroo, Koala, Lion, Penguin, Pink Pig, Panda, Big Grey Wolf, Gold Bunny, Blue Star, Star Unicorn, Sleepy Unicorn, Skeleton, Blue Bunny, White Bunny, 3D Pink Bunny, 3D Blue Bunny, Grey Hare, Star Bunny, Leopard Bear, Brown Monkey, Chipmunk, Deer, Tiger, Yellow Tiger, Giant Panda, Long-Tail Monkey, Shiba, Lamb, Grey Hippo, Dalmatian, Grey Wolf, Rainbow Unicorn, Red Dino, Cow, Green Dino, Pink Dino, Grey Shark, Blue Shark, Raccoon, Turtle.

More from the Baby collection

For little ones who love anything with wheels, the Road Trip Romper is a plush hooded car romper — a red racer or a tow truck — with a front zip, in sizes from 0–12 months to 2–4 years. And for bath time once they can stand while holding on, the Duckling Bath Stand gives them a duck-shaped handrail to hold in the shower while you wash with both hands — always within arm's reach.

Frequently asked questions

Written by the Solis Fortune editorial team. Specifications quoted are the published manufacturer figures for the products linked above; where a supplier publishes no figure we say so rather than estimate one. Regulatory summaries are general information, not legal advice — check the rules that apply where you live before you buy.