Sizing guide
Choose the fit she will love
The onesie is designed loose. When you're between sizes, size up for that slouchy lounge look.
| Size | Best for height | Fit notes |
|---|---|---|
| S | 4'11" – 5'3" | Snug-loose one-piece fit |
| M | 5'3" – 5'7" | Our most popular size |
| L | 5'7" – 5'11" | Roomy through hips and sleeves |
| XL | 5'11" – 6'2" | Maximum slouch and coverage |
How it's cut
Loose-fitting one-piece with wide sleeves, a full-length body and a hooded collar with character details. There's plenty of room for layering a t-shirt or leggings underneath on very cold nights.
Between sizes?
Size up. Nobody has ever told us their monster onesie was too roomy — the relaxed shape is the whole point.
Monster styles
Every size comes in eight big-mouth monster characters. The fit is identical across styles, so pick purely on personality.
Ready for cozy monster nights?
Free shipping · Money-back guarantee · Secure checkout
Shop the pajamas