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Oneder the Sea Onesie®, Under the Sea Party, Whale Birthday shirt, 1st Birthday, Girl Birthday Shirt, Ocean Party, Mermaid Birthday, I am 1
Oneder the Sea Onesie®, Under the Sea Party, Whale Birthday shirt, 1st Birthday, Girl Birthday Shirt, Ocean Party, Mermaid Birthday, I am 1 a variety of children's clothing options, including short sleeve bodysuits, long sleeve bodysuits, short sleeve t-shirts, long sleeve t-shirts, girls' fitted t-shirts, fringe dresses, and ruffle sleeve bodysuits. a baby wearing a short sleeve and long sleeve onesie. The image is a children's size chart, specifically part 2 of 2, featuring various sizes of children's clothing such as short sleeves, long sleeves, and fringe dresses. The image is a collage of multiple images, and I will describe each one individually. There is no need to describe each image individually, as it would be redundant and vague. Instead, I will describe the image as a whole, focusing on the content and context rather than individual elements. The image is a collage of various images related to the Bella Lexi Boutique, including a social media post, a website, and an email address. The image does not contain any text that can be described in fewer than 500 characters.
Oneder the Sea Onesie®, Under the Sea Party, Whale Birthday shirt, 1st Birthday, Girl Birthday Shirt, Ocean Party, Mermaid Birthday, I am 1
a variety of children's clothing options, including short sleeve bodysuits, long sleeve bodysuits, short sleeve t-shirts, long sleeve t-shirts, girls' fitted t-shirts, fringe dresses, and ruffle sleeve bodysuits.
a baby wearing a short sleeve and long sleeve onesie.
The image is a children's size chart, specifically part 2 of 2, featuring various sizes of children's clothing such as short sleeves, long sleeves, and fringe dresses.
The image is a collage of multiple images, and I will describe each one individually. There is no need to describe each image individually, as it would be redundant and vague. Instead, I will describe the image as a whole, focusing on the content and context rather than individual elements.
The image is a collage of various images related to the Bella Lexi Boutique, including a social media post, a website, and an email address. The image does not contain any text that can be described in fewer than 500 characters.
On Sale

Oneder the Sea Onesie®, Under the Sea Party, Whale Birthday shirt, 1st Birthday, Girl Birthday Shirt, Ocean Party, Mermaid Birthday, I am 1

$ 24.98

Under the Sea First Birthday Onesie®. Such a pretty first birthday bodysuit or t-shirt for your little one! It features a delicate watercolor whale with under the sea accents and the words 'One der the Sea' with your little one's name. Since all of Bella Lexi™ designs are printed directly onto the garments of your choice, the designs won't peel, crack or fade! This under the sea theme birthday design also makes a wonderful gift! Your little one will look adorable for her special day!

★★★★★
Loved by 47,000+ families
Real reviews from real Bella Lexi customers
★★★★★

“So cute! Perfect for my son's birthday. The quality was amazing and it arrived right on time.”

Etsy Customer · Birthday
★★★★★

“Just darling and PERFECT for my boy's first rodeo! Fast shipping!”

Rachel J. · Birthday
★★★★★

“Just as described. Very fast shipping! Cannot wait for the party! The shirt is adorable!”

Etsy Customer · Birthday
See all 47,000+ reviews →
Category: Girl Birthdays, The Birthday Shop | Custom Outfits & Party Tees
Description

Under the Sea First Birthday Onesie®. Such a pretty first birthday bodysuit or t-shirt for your little one! It features a delicate watercolor whale with under the sea accents and the words 'One der the Sea' with your little one's name. Since all of Bella Lexi™ designs are printed directly onto the garments of your choice, the designs won't peel, crack or fade! This under the sea theme birthday design also makes a wonderful gift! Your little one will look adorable for her special day!

Shipping

Handcrafted & Made to Order
Every Bella Lexi item is custom-made just for you. No shelf stock, no shortcuts — just quality pieces printed on demand so we can offer the level of personalization our customers love.

  • Processing Time: Please allow up to 5 business days for your order to be made before it ships.
  • Custom Requests: Want to change a color, add a name, or tweak a design? Contact us before ordering and we'll make it happen.
  • Need it Fast? Message us before purchasing to discuss rush options. Additional fees may apply.
Sizing / Fit

Finding Your Fit
All measurements vary by garment style. For the best fit, we recommend:

  • View our Size Guide: See measurements for every garment style at bellalexi.com/pages/size-guide
  • Size Up: When in between sizes, always go up — your little one will grow into it!
  • Ask Us First: Not sure? Send us a message before ordering. We're happy to help you find the right size.

Our Garments
We use high-quality brands to create your custom pieces.

  • Onesies® Brand: We use genuine Gerber Onesies® brand bodysuits (Short Sleeve, sizes 0–3M and 3–6M). Onesies® is a registered trademark of Gerber Childrenswear LLC.

All Sales are Final
Every item is custom-made just for you. We cannot accept returns or exchanges due to sizing. Please review the size guide carefully before ordering!

Care / Quality

Professional Quality, Baby Safe
At Bella Lexi Boutique we use direct-to-garment printing technology — no vinyl, no transfers, no cracking or peeling. The design becomes part of the fabric.

Our inks are eco-friendly, non-toxic, and Oeko-Tex Standard 100 certified at Class 1 — the highest safety rating, approved for sensitive newborn skin.

Washing Instructions

  • Turn Inside Out before washing to protect the print.
  • Machine Wash Cold with like colors.
  • No Bleach or harsh detergents.
  • Tumble Dry Low or hang to air dry for best results.
Reviews