Mr. FatRat’s Chonky Rat in a Sweater: A Free Knitting Pattern for Your New Favorite Little Dumpling

If you’ve been anywhere near the knitting corner of the internet lately, you already know that stuffed animal patterns have taken on a life of their own. From tiny woodland creatures to oversized plushies, knitters everywhere are reaching for their needles and their fluffiest yarn to create something soft, squishy, and ridiculously charming. And nothing — absolutely nothing — captures the hearts of knitters and non-knitters alike quite like a chonky rat in a miniature sweater.

This pattern is inspired by Mr. FatRat, and it delivers exactly what the name promises: a rotund, squeezable little rodent with the kind of energy that says “I have eaten all the cheese and I have zero regrets.” This is a beginner-friendly to intermediate knitting pattern that produces a stuffed amigurumi-style rat standing roughly five to six inches tall (not counting his ears), dressed in a tiny ribbed sweater that you can customize in any color you like.

Whether you’re making him for yourself, gifting him to a rat lover in your life, or adding him to a growing collection of knitted critters, Mr. FatRat is here to deliver maximum charm with manageable construction. Let’s get into it.

Materials You’ll Need

Before you cast on, gather your supplies. Part of what makes this pattern so approachable is that it doesn’t require anything exotic or expensive. Most of these materials are things you may already have in your stash.

For the rat’s body:
You’ll need approximately 100 yards of bulky weight (size 5) yarn in a soft, smooth finish. Gray, brown, cream, and even white are all wonderful choices. The smoother the yarn, the cleaner your stitches will read, which matters especially when you’re working at a small scale. Avoid fuzzy or boucle yarns for your first attempt, as they make it harder to count stitches and seam cleanly.

For the sweater:
You’ll need approximately 50 yards of worsted weight (size 4) yarn in a contrasting or coordinating color. This is where you can really have fun. A classic cream sweater gives serious vintage teddy bear vibes. A deep forest green sweater makes him look like he’s ready for a cozy autumn weekend. Hot pink, cobalt blue, mustard yellow — Mr. FatRat looks distinguished in all of them.

Needles:
A set of US size 7 (4.5mm) double-pointed needles or a short circular needle for the body, and US size 6 (4.0mm) needles for the sweater ribbing and body panels. If you prefer to work flat and seam, straight needles in the same sizes will work perfectly well.

Other supplies:
A pair of 9mm or 10.5mm black safety eyes (or embroidered eyes if you’re making this for a small child), polyester fiberfill stuffing, a yarn needle for seaming and weaving in ends, stitch markers, and scissors. A small amount of pink yarn or embroidery floss for the nose and inner ears is also helpful.

Gauge and Finished Size

Gauge: approximately 16 stitches and 22 rows per 4 inches in stockinette with bulky yarn on US size 7 needles.

Finished size: approximately 5 to 6 inches tall (body and head) with a 3.5 inch circumference at the widest point of the belly. He is intentionally round. That is not a flaw. That is the entire point.

Pattern Notes

This pattern is worked primarily in the round using a modified amigurumi construction. The body and head are worked as one continuous piece, then stuffed and closed. The legs, arms, ears, and tail are worked separately and attached. The sweater is worked flat in two panels and seamed, then slipped over the body.

Throughout this pattern, increases are made using the M1 (make one) method unless otherwise noted, and decreases use k2tog (knit two together). All rounds are joined unless the pattern specifies working flat.

If you are new to working in the round on double-pointed needles, this pattern is actually a wonderful place to learn. Because the pieces are small, you’re never managing a huge number of stitches at once, and each section moves quickly. A small mistake is easy to frog and redo without losing too much time.

The Body

Cast on 6 stitches. Divide evenly across your double-pointed needles and join to work in the round, being careful not to twist.

Round 1: Knit all stitches.
Round 2 (increase round): [K1, M1] around — 12 stitches.
Round 3: Knit all stitches.
Round 4 (increase round): [K1, M1] around — 24 stitches.
Round 5: Knit all stitches.
Round 6 (increase round): [K2, M1] around — 32 stitches.
Rounds 7–10: Knit all stitches.
Round 11 (increase round): [K4, M1] around — 40 stitches.
Rounds 12–18: Knit all stitches. (This is where the satisfying chonk lives. These rounds build out that beautiful round belly.)
Round 19 (decrease round): [K6, k2tog] around — 35 stitches.
Round 20: Knit all stitches.
Round 21 (decrease round): [K5, k2tog] around — 30 stitches.
Round 22: Knit all stitches.
Round 23 (decrease round): [K4, k2tog] around — 25 stitches.

At this point, insert your safety eyes if using them. Position them symmetrically at approximately round 20 counting from the cast-on end, spaced about 8 to 10 stitches apart. This is also the time to add a small amount of stuffing to the lower body before the opening becomes too small to work through comfortably.

Round 24 (decrease round): [K3, k2tog] around — 20 stitches.
Round 25: Knit all stitches.
Round 26 (increase round): [K2, M1] around — 27 stitches. (This creates the slight shelf between body and head.)
Round 27: Knit all stitches.
Round 28 (increase round): [K3, M1] around — 36 stitches.
Rounds 29–34: Knit all stitches.
Round 35 (decrease round): [K4, k2tog] around — 30 stitches.
Round 36: Knit all stitches.
Round 37 (decrease round): [K3, k2tog] around — 24 stitches.
Round 38 (decrease round): [K2, k2tog] around — 18 stitches.

Add the remaining stuffing now, making sure to fill the head firmly so it holds its round shape. Don’t be shy here — a well-stuffed head photographs beautifully and keeps the ears perky.

Round 39 (decrease round): [K1, k2tog] around — 12 stitches.
Round 40 (decrease round): [k2tog] around — 6 stitches.

Cut yarn, thread through remaining stitches, pull tight, and secure. Weave in the end.

The Ears (Make Two)

Cast on 8 stitches on straight or double-pointed needles.

Row 1: Knit all stitches.
Row 2: Purl all stitches.
Row 3: K1, k2tog, k2, k2tog, k1 — 6 stitches.
Row 4: Purl all stitches.
Row 5: K1, k2tog, k2tog, k1 — 4 stitches.
Row 6: [P2tog] twice — 2 stitches.

Cut yarn and pull through remaining stitches. If desired, use pink yarn or embroidery floss to work a few stitches in the center of each ear for that classic rat ear detail. Fold the cast-on edge slightly and seam to close, creating a gentle curve. Set ears aside.

The Arms (Make Two)

Cast on 5 stitches and join to work in the round.

Rounds 1–8: Knit all stitches.

Stuff lightly — just enough to give them a little body without making them stiff. Cut yarn, thread through stitches, pull closed. These little arms will be attached in a position that suggests Mr. FatRat is either reaching for something delicious or giving a very small hug. Both are acceptable.

The Legs (Make Two)

Cast on 8 stitches and join to work in the round.

Round 1 (increase round): [K1, M1] around — 16 stitches.
Rounds 2–4: Knit all stitches. (This creates the rounded little foot.)
Round 5 (decrease round): [K2, k2tog] around — 12 stitches.
Rounds 6–10: Knit all stitches.

Stuff the foot firmly and the leg lightly. Cut yarn, thread through stitches, pull closed. His legs are short and wide, which is both structurally appropriate and aesthetically perfect.

The Tail

Using a crochet hook or two double-pointed needles as a tiny I-cord setup, cast on 3 stitches and work an I-cord for approximately 4 to 5 inches. Cast off and leave a long tail for attaching. A slight natural curl is charming and can be encouraged by blocking over a pencil.

The Sweater

The sweater is the crowning glory of this project and the thing that will make everyone who sees Mr. FatRat immediately want to know where to find the pattern. It is worked flat in two identical panels and seamed at the sides, leaving openings for the arms.

Front and Back Panel (Make Two):

Using your worsted weight yarn and size 6 needles, cast on 22 stitches.

Rows 1–4: [K2, P2] ribbing across, ending with K2. (This creates the sweater hem.)
Row 5 (wrong side): Purl all stitches.
Rows 6–16: Work in stockinette (knit on right side, purl on wrong side).

For the neckline shaping on the front panel only:
Row 17: K8, bind off center 6 stitches, K8.
Row 18: Working each shoulder separately, purl to end on each side.
Row 19: K2tog at each neck edge, knit to end — 7 stitches per shoulder.
Row 20: Purl all stitches.
Bind off each shoulder separately.

For the back panel, simply work rows 17–20 in stockinette without the neckline shaping, then bind off all 22 stitches.

Sleeves (Make Two):

Cast on 16 stitches.
Rows 1–3: [K2, P2] ribbing.
Rows 4–10: Stockinette.
Bind off.

Seam the sweater panels at the shoulders, then set in the sleeves, then seam the sides and sleeves leaving openings at the sides for the arms. Slide the sweater over Mr. FatRat’s body. Because he is knitted, the sweater will fit snugly without needing to be sewn down, though a few tacking stitches at the back can help it stay positioned if you prefer.

Assembly

Lay out all of your pieces before you begin seaming to make sure everything looks proportionate and nothing is missing. Attach the ears to the top of the head, spacing them about an inch apart and angling them very slightly outward for maximum expressiveness. Attach the arms just below the sweater neckline, on either side of the body. Attach the legs at the base of the body, angled slightly forward so he can sit up on his own (stuff the bottom of the body firmly to help with this). Attach the tail at the very back base of the body.

Use your pink yarn or embroidery floss to add a small nose just above where the eyes sit, working a few straight stitches in a tight triangular cluster. Step back and look at him. There he is. Your chonky little rat in a sweater. He is perfect.

Customization Ideas

One of the most delightful things about this pattern is how much room there is to make Mr. FatRat entirely your own. Here are a few directions people have taken with this design that turned out wonderfully.

Color blocking the sweater: Try working the ribbing in one color and the body of the sweater in another. A cream-and-tan combination looks especially cozy.

Adding a collar: Cast on 40 stitches after finishing the sweater and work four rows of seed stitch before binding off. Wrap it around the neckline and tack in place.

Stripes: Swap colors every two rows during the stockinette section of the sweater for a classic striped look.

A name tag: Use a small piece of felt cut into a rectangle and written on with a fabric pen to give your rat an official name. Stitch it onto the front of the sweater like a little label.

Making a family: Scale the pattern up or down by adjusting needle size and yarn weight. A fingering weight version with US size 2 needles produces a tiny pocket-sized rat. A super bulky version with size 13 needles produces a rat the size of a small throw pillow. Both are valid life choices.

A Note on Yarn Substitutions

The pattern is written for bulky weight yarn, but honestly, this rat is forgiving. If you’re working from stash and only have worsted or DK weight, simply size down your needles to close up the fabric so the stuffing doesn’t show through, and be aware your finished rat will be smaller than listed. Conversely, if you go up to a super bulky, you’ll end up with something magnificently oversized. For the sweater, any smooth yarn in the worsted-weight range will work beautifully, and this is a great place to use up those single skeins you’ve been holding onto, not quite sure what to do with.

Finishing and Care

Weave in all ends carefully, especially any that are near the seams on the sweater where they might be visible. Block the sweater lightly by misting with water and smoothing it into shape before slipping it onto the body — this evens out the stitches and gives the whole thing a much more polished look.

Mr. FatRat is not machine washable due to the stuffing and safety eyes, but his sweater can be hand washed gently if needed. Spot cleaning the body with a damp cloth is the safest approach.

Final Thoughts

There is something genuinely joyful about this project. Maybe it’s the combination of the round, compact shape with the tiny sweater. Maybe it’s the ears, slightly too large and impossibly cute. Maybe it’s the tail, curling off behind him like a little question mark. Whatever it is, Mr. FatRat tends to gather an audience while being made, and once finished, rarely stays on a shelf. He gets picked up, carried around, set on desks next to computer monitors, placed prominently on bookshelves, and occasionally taken to work in a bag.

If you make your own chonky rat in a sweater, consider sharing it with the tag #mrfatrat or posting it in your favorite knitting community. There is a specific kind of delight that comes from seeing a whole internet full of slightly different, individually named little rats in their individual sweaters, each one made by someone who took some yarn and some needles and some time and turned it into something that will outlast the original skein by decades.

Happy knitting. Mr. FatRat is waiting to be born.