400gsm brushed fleece
Twice the loft of a standard onesie, brushed both sides so it stays soft past wash fifty.
4.9
Cozy Monster Onesie
400gsm brushed fleece, horned hood, two deep pockets, and a back-flap that actually stays shut.
$59.99
$100.00
40% off
- Free shipping over $75
- 30-day returns
- Secure checkout
Details & fit
400gsm brushed cotton-modal fleece with a soft-lock zip, horned hood and two deep front pockets. Relaxed fit — size down for a closer cut.
Shipping & returns
Free carbon-neutral shipping over $75, otherwise a flat $6. Orders leave in 1–2 business days. Wear it thirty nights; if it isn't the kozyest thing you own, return it free.
Care
Machine wash cold on a gentle cycle, tumble dry low or hang to dry. No fabric softener — it flattens the pile.
Designed to be lived in
Gusseted shoulders, no-scratch seams, a hood that holds its horns and pockets that hold your phone.
One product, done right
No seasonal churn. We make one onesie, refine it every year, and stand behind it for 30 days.
See it on
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60 seconds of fleece, horns and pockets.
4.9
Loved by 1,428 sleepers
Real photos and videos from customers. 96% would buy again.
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Maya R. Verified buyer2 weeks ago
★★★★★Softer than it looks
I own three now. It survived a year of daily winter wear and still looks new.
D
Dan K. Verified buyer1 month ago
★★★★★Bought it as a joke, wears it daily
Bought it as a gag gift for my husband. He wears it more than actual clothes now.
P
Priya S. Verified buyer3 weeks ago
★★★★★Genuinely heavyweight
The fleece is properly heavy — nothing like the thin onesies I've tried before. Worth every cent.
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Tom H. Verified buyer6 weeks ago
★★★★★The hood is the best part
Horns hold their shape after a dozen washes. Pockets fit a phone and a bag of chips.
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Ariana L. Verified buyer2 months ago
★★★★★Runs true to size
I'm 5'4" and size S is perfect with room for socks. The exchange was free and took two days.
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Marcus W. Verified buyer2 months ago
★★★★★Winter uniform
House is cold, heating bill isn't. This thing paid for itself in January.
Straight from customers
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Our story
We only ever wanted to make one thing.
Kozy Monsters started in a Portland apartment with one badly-sewn prototype and a stubborn belief that loungewear should last longer than a winter.
Six years and eleven revisions later, it's still the only thing we sell. Sewn in a family-run factory in Portugal, shipped in recycled packaging, guaranteed for thirty nights.
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Questions, answered
How does the sizing run?
True to size with a relaxed drape. Between sizes and want a closer fit? Size down.
Is it too warm to sleep in?
Breathable and moisture-wicking, so most people sleep in it year-round. The full-length zip vents easily.
What if it doesn't fit?
Exchanges and returns are free within 30 days, worn or unworn.
How long is shipping?
1–2 business days to leave the studio, then 2–5 days in the US. Free over $75.
Where is it made?
A family-run factory in northern Portugal, from OEKO-TEX certified fabric.