The Starlight Serenade Mermaid Tail Blanket: A Free Knitting Pattern for a Cozy, Textured Baby Cocoon

Introducing the Starlight Serenade Mermaid Tail Blanket

Wrap your little one in the magic of the sea with this uniquely textured mermaid tail blanket. Featuring a mesmerizing wave stitch pattern and a soft, modern color palette, this free knitting pattern creates a cozy, heirloom-quality cocoon that's perfect for snuggling and photos. The blanket is worked flat from the top (hip) down to the tail tip, then seamed up the back, making it an accessible project for adventurous beginners. The wave stitch pattern creates a beautiful, undulating texture reminiscent of ocean waves, while the gradual shaping at the tip gives it that iconic mermaid silhouette.

Materials Needed

• Yarn: Worsted weight (#4) yarn in two colors:
  • Main Color (MC) - 350 yards (e.g., soft seafoam green)
  • Contrast Color (CC) - 150 yards (e.g., creamy white)
  • Suggested: Lion Brand Heartland in 'Olympic' and 'Yosemite'
• Needles: US Size 8 (5.0 mm) knitting needles (or size to obtain gauge)
• Notions: Tapestry needle, stitch markers
• Gauge: 18 stitches and 24 rows = 4 inches in stockinette stitch (blocked). Wave stitch pattern gauge: 20 stitches and 28 rows = 4 inches.

Step-by-Step Instructions

Size and Abbreviations

Size: Newborn to 3 months (approx. 20 inches long, 14 inches wide at hips, 8 inches at tail tip).

Abbreviations:

• CO: Cast on
• K: Knit
• P: Purl
• St(s): Stitch(es)
• MC: Main Color
• CC: Contrast Color
• RS: Right side
• WS: Wrong side
• K2tog: Knit two together
• P2tog: Purl two together
• Yo: Yarn over
• Sl: Slip stitch purlwise
• Rep: Repeat

Pattern Notes

• The blanket is worked flat from the top (hip) down to the tail tip, then seamed up the back.
• The wave stitch pattern creates a beautiful, undulating texture reminiscent of ocean waves.
• Carry the unused yarn loosely up the side when changing colors.

Instructions

Begin the Blanket Body

With MC, CO 60 sts.

• Row 1 (RS): K all sts.
• Row 2 (WS): P all sts.
• Row 3 (RS): K all sts.
• Row 4 (WS): P all sts.
• Row 5 (RS): K all sts.
• Row 6 (WS): P all sts.

Begin Wave Stitch Pattern

• Row 7 (RS, MC): K1, *yo, K2tog, K1, yo, K2tog, K1, yo, K2tog, K1, yo, K2tog, K1; rep from * to last st, K1. (60 sts)
• Row 8 (WS, MC): P all sts.
• Row 9 (RS, CC): K1, *K2tog, yo, K1, K2tog, yo, K1, K2tog, yo, K1, K2tog, yo, K1; rep from * to last st, K1.
• Row 10 (WS, CC): P all sts.
• Row 11 (RS, MC): K1, *K1, yo, K2tog, K1, yo, K2tog, K1, yo, K2tog, K1, yo, K2tog; rep from * to last st, K1.
• Row 12 (WS, MC): P all sts.
• Row 13 (RS, CC): K1, *K2tog, K1, yo, K2tog, K1, yo, K2tog, K1, yo, K2tog, K1, yo; rep from * to last st, K1.
• Row 14 (WS, CC): P all sts.

Repeat Rows 7-14 for the wave stitch pattern until the piece measures approximately 16 inches from the cast-on edge, ending with a WS row (Row 8, 10, 12, or 14).

Shape Tail Tip

Continue in stockinette stitch (K on RS, P on WS) with MC only.

• Row 1 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (58 sts)
• Row 2 (WS): P all sts.
• Row 3 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (56 sts)
• Row 4 (WS): P all sts.
• Row 5 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (54 sts)
• Row 6 (WS): P all sts.
• Row 7 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (52 sts)
• Row 8 (WS): P all sts.
• Row 9 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (50 sts)
• Row 10 (WS): P all sts.
• Row 11 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (48 sts)
• Row 12 (WS): P all sts.
• Row 13 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (46 sts)
• Row 14 (WS): P all sts.
• Row 15 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (44 sts)
• Row 16 (WS): P all sts.
• Row 17 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (42 sts)
• Row 18 (WS): P all sts.
• Row 19 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (40 sts)
• Row 20 (WS): P all sts.
• Row 21 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (38 sts)
• Row 22 (WS): P all sts.
• Row 23 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (36 sts)
• Row 24 (WS): P all sts.
• Row 25 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (34 sts)
• Row 26 (WS): P all sts.
• Row 27 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (32 sts)
• Row 28 (WS): P all sts.
• Row 29 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (30 sts)
• Row 30 (WS): P all sts.
• Row 31 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (28 sts)
• Row 32 (WS): P all sts.
• Row 33 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (26 sts)
• Row 34 (WS): P all sts.
• Row 35 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (24 sts)
• Row 36 (WS): P all sts.
• Row 37 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (22 sts)
• Row 38 (WS): P all sts.
• Row 39 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (20 sts)
• Row 40 (WS): P all sts.
• Row 41 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (18 sts)
• Row 42 (WS): P all sts.
• Row 43 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (16 sts)
• Row 44 (WS): P all sts.
• Row 45 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (14 sts)
• Row 46 (WS): P all sts.
• Row 47 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (12 sts)
• Row 48 (WS): P all sts.
• Row 49 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (10 sts)
• Row 50 (WS): P all sts.
• Row 51 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (8 sts)
• Row 52 (WS): P all sts.
• Row 53 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (6 sts)
• Row 54 (WS): P all sts.
• Row 55 (RS): K2, K2tog, K to last 4 sts, K2tog, K2. (4 sts)
• Row 56 (WS): P all sts.
• Row 57 (RS): K2tog twice. (2 sts)
• Row 58 (WS): P2tog. (1 st)

Cut yarn, pull through last stitch.

Finishing

Fold the blanket in half lengthwise with RS together. Using MC and tapestry needle, mattress stitch the back seam from the cast-on edge down to the tip. Weave in all ends. Block gently to open up the wave stitch pattern.