Big Mouth Monster Crochet Pattern: Kawaii Amigurumi Keychain Tutorial (PDF Download)
If you’ve ever scrolled through a craft fair table or an Etsy shop and spotted a tiny, wide-eyed monster dangling from someone’s bag, you already know the magnetic pull of kawaii amigurumi. These little creatures are impossible to ignore. They’re soft, they’re expressive, and they carry that particular brand of cute-meets-creepy energy that makes people reach out and pick them up before they’ve even registered what they’re doing. This big mouth monster crochet pattern is exactly that kind of project — a chunky-cheeked, wide-mawed little beast that looks intimidating in theory but ends up being one of the most charming things you’ll ever attach to a zipper pull.
This tutorial walks you through the entire process of making your own kawaii amigurumi monster keychain from start to finish. Whether you’re a seasoned crocheter looking for a quick and satisfying project or someone who finished their first granny square two weeks ago and is ready to go three-dimensional, this pattern is approachable, fun, and genuinely addictive. Once you finish one, you’ll want to make ten more in every color combination you can think of.
What Makes Kawaii Amigurumi So Popular Right Now
Amigurumi — the Japanese art of crocheting or knitting small stuffed creatures — has been a beloved craft for decades, but it’s experiencing a genuine renaissance right now, and for good reason. The combination of fiber arts and character design scratches a creative itch that a lot of makers didn’t even know they had. You get the meditative rhythm of crochet alongside the satisfaction of building a personality into every stitch.
The kawaii aesthetic, which centers on maximizing cuteness through oversized eyes, rounded shapes, and pastel or high-contrast color palettes, translates beautifully into amigurumi. Monsters are a particularly beloved subject because they give you permission to get weird. You can add too many teeth, make the eyes mismatched, give your creature three arms if you feel like it — the “monster” label is basically a creative hall pass. And when you shrink all of that down to keychain size, you get something that’s simultaneously ridiculous and completely irresistible.
The PDF download format has also changed how crafters engage with patterns. Having a clean, printable version you can annotate, mark up, and reference without needing to scroll through a phone screen while your hands are occupied makes the whole experience smoother. A well-formatted PDF crochet pattern is genuinely worth its price, and this one is designed with that in mind.
Materials You’ll Need
Before diving into the stitches, gather your supplies. One of the most satisfying things about amigurumi keychain projects is how little material they actually require. You can often make a complete monster from yarn scraps left over from other projects.
For this big mouth monster, you’ll need a small amount of worsted weight yarn in your main body color, plus contrast colors for the mouth lining, teeth, and any accent details you want to add. Sport or DK weight yarn works too if you adjust your hook size — the finished keychain will just be slightly smaller, which is charming in its own right.
In terms of hook size, a 3.5mm or 4mm crochet hook is ideal for worsted weight yarn when making amigurumi. You want your tension to be tight enough that the stuffing won’t show through the gaps between stitches, but not so tight that your hands cramp up after three rounds. If you’ve made amigurumi before, you likely already have a sense of what hook size creates the right fabric for your preferred yarn.
You’ll also need polyester fiberfill stuffing, a pair of safety eyes in 6mm or 8mm size depending on how large you want your monster’s face to be, a yarn needle for seaming and weaving in ends, stitch markers (locking markers work best), scissors, and a keychain ring or lobster clasp to attach to your finished piece. Some crafters add a small length of chain or a jump ring between the keychain hardware and the monster itself to give it a bit more swing, which is an entirely optional but satisfying finishing touch.
If you want to add extra personality, consider picking up some small amounts of contrasting yarn for horns, tails, or extra limbs. Black yarn or embroidery floss is useful for adding pupils, eyebrow details, or mouth stitching if you prefer embroidered features over safety eyes.
Understanding the Basic Stitches
This pattern uses a handful of standard crochet stitches that appear in virtually every amigurumi project. If you already know these, feel free to skip ahead. If any of them are new to you, take fifteen minutes to practice them on a small swatch before starting the monster.
The foundation of amigurumi is the magic ring, sometimes called the magic circle or adjustable ring. This technique lets you start crocheting in the round without leaving a hole at the center of your work, which is exactly what you want when making a closed spherical shape like a monster’s head. If you’ve struggled with the magic ring before, try the two-loop version rather than the single loop, and pull the tail end snugly after your first round to close any gap.
Single crochet is the main stitch throughout this pattern. It creates a dense, sturdy fabric that holds its shape well when stuffed and sits neatly on the surface of the finished piece. All of the increases and decreases in this pattern are also worked in single crochet — increases by working two stitches into the same stitch, decreases by using the invisible decrease technique, which involves inserting your hook through the front loops only of two consecutive stitches before drawing through and completing the stitch.
The invisible decrease (also called the slip stitch decrease by some crafters, though the technique is slightly different) creates a much flatter, less visible seam line than a standard single crochet decrease, which leaves a small bump on the surface. For small amigurumi, that bump can be quite noticeable, so using the invisible decrease consistently will give your monster a smoother, more professional finish.
Slip stitches appear at the joining points in some sections of this pattern and are used to attach separate pieces. Chain stitches create small loops for attaching your keychain hardware.
The Pattern: Big Mouth Monster Kawaii Amigurumi Keychain
The following instructions are written in US crochet terminology. “MR” means magic ring, “sc” means single crochet, “inc” means increase (two single crochets in one stitch), “dec” means invisible decrease, “sl st” means slip stitch, and numbers in parentheses at the end of a row indicate the total stitch count for that round.
Head and Body (worked as one piece)
Start with your main body color yarn.
Round 1: MR, 6 sc into ring, pull tight. (6)
Round 2: Inc in each stitch around. (12)
Round 3: [Sc 1, inc] repeat 6 times. (18)
Round 4: [Sc 2, inc] repeat 6 times. (24)
Round 5: [Sc 3, inc] repeat 6 times. (30)
Rounds 6 through 10: Sc in each stitch around. (30) — work 5 rounds even.
Now is the time to attach your safety eyes. For this monster, the eyes sit in round 7 or 8, separated by about 6 to 8 stitches depending on how wide you want the face to feel. Push the posts through a single stitch each, position them until you’re happy with the expression, and then attach the washers firmly on the inside. Once the washers are on, the eyes cannot be repositioned, so take a moment to look at the face from a few different angles before committing.
Round 11: [Sc 3, dec] repeat 6 times. (24)
Round 12: [Sc 2, dec] repeat 6 times. (18)
At this point, begin stuffing your monster firmly with fiberfill. You want it to feel solid and hold its shape without being so packed that the surface fabric stretches and you can see the white stuffing through the stitches. Add stuffing gradually and check the shape as you go. The body should be nicely rounded and slightly wider than it is tall.
Round 13: [Sc 1, dec] repeat 6 times. (12)
Round 14: Dec 6 times. (6)
Fasten off, leaving a short tail. Use your yarn needle to weave the tail through the front loops of the remaining six stitches, draw up snugly to close the gap, and weave in the end on the inside of the piece.
The Mouth
This is the feature that gives the big mouth monster its name and its personality. The mouth is worked separately and sewn onto the face, which gives you the flexibility to position it however you like before committing to the seam.
Switch to your mouth lining color — a bright coral, deep red, hot pink, or even a lime green all work beautifully depending on the overall color story of your monster.
Chain 8.
Row 1: Starting in the second chain from the hook, sc across. (7)
Row 2: Ch 1, turn. Sc across. (7)
Row 3: Ch 1, turn. Dec, sc 3, dec. (5)
Row 4: Ch 1, turn. Dec, sc 1, dec. (3)
Fasten off and leave a long tail for sewing. This creates a small oval or teardrop-shaped mouth piece. Before sewing it to the face, decide how open you want the monster to look. A mouth positioned low on the face with the wider end pointing outward creates a wide, grimacing expression. Rotated slightly, it reads as more of a cheeky grin.
Teeth (make 2 to 4 depending on preference)
Switch to white or off-white yarn.
Using a magic ring, ch 2, work 3 half double crochets into the ring, sl st to close. Pull tight. Fasten off, leaving a tail for attachment.
These tiny half-circle teeth get tucked under the edge of the mouth piece before you sew it down, creating the illusion that they’re growing from inside the mouth. Position them with their flat edges along the top or bottom of the mouth opening, or both, for a fully toothed look.
Finishing the Face
Thread your yarn needle with the long tail from the mouth piece and pin it to the face below the eyes. The bottom edge of the mouth should sit somewhere around rounds 11 or 12, though you can adjust this. Use small whipstitches around the perimeter of the mouth piece, tucking the teeth into position as you go and securing them in place. When the mouth is fully attached, weave in all remaining ends.
Optional Horns (make 2)
Using a contrast color, MR and work 4 sc into ring, then work 1 inc per round for 2 more rounds (or simply work 3 rounds of 4 sc for a small stubby horn). Fasten off with a tail for sewing. Flatten the open end and sew flat to the top of the head, spaced evenly.
Attaching the Keychain Hardware
To add your keychain ring, thread a length of the main color yarn through your needle and draw it through the topmost point of the head (the very center of round 1, essentially). Work a few stitches to create a small loop strong enough to hold the hardware, knot securely, and weave in the end. Attach your keychain ring or lobster clasp through this loop.
Alternatively, you can use a small jump ring threaded directly through a surface stitch at the top of the head and then attached to your keychain hardware — this creates a cleaner look if you have basic jewelry-making supplies on hand.
Customization Ideas to Make It Your Own
Half the fun of a monster pattern is that there’s no wrong answer when it comes to personalization. Here are some directions you might take this little creature.
Color blocking the body in two colors, switching halfway through the rounds, creates a striking visual effect that’s simple to execute — just join a new color at any point in the even rounds and carry the old color along the inside until you decide whether you’ll need it again. Color changes in amigurumi work best in the round when you join your new color on the last pull-through of the stitch before the color change.
Adding a tail made from a short braided length of yarn, or a tiny crochet tube of four to six single crochets in the round, gives your monster extra character and a bit of extra movement when it dangles from a bag or keys. A small crochet tail can be worked as a simple tube: MR, 4 sc, then work rounds of 4 sc for however long you want the tail, fasten off with a tail for sewing, and attach to the base of the body.
Changing the eye size or style completely transforms the personality. Larger eyes read as more surprised or innocent; smaller eyes suggest something more scheming. You can also embroider eyes using black yarn if you’re making this for a young child and prefer to avoid safety eyes as a precaution, or if you just prefer the softer look of stitched features.
Experimenting with texture by adding bobble stitches as warts, using a fuzzy or bouclé yarn for a furry monster effect, or working the surface in back loops only for one round to create a ridge line are all techniques that can elevate a simple pattern into something genuinely unique.
Tips for Getting the Best Results
Gauge matters more in amigurumi than many crafters expect. Because you’re stuffing the finished piece, a fabric that’s too loose will stretch visibly and the white stuffing will peek through. Swatch a small circle before starting and adjust your hook size down if you can see gaps between the stitches.
Consistent tension throughout a piece prevents lumpy or lopsided results. If you find your tension loosening as you go — which often happens when you get more comfortable with a pattern — try consciously pulling each stitch slightly tighter, or periodically check your swatch against earlier rounds.
Stitch markers are your best friend in the round. Place one at the beginning of each round and move it up as you complete each round. Without a marker, it’s extremely easy to lose track of where a round starts and ends, which can throw off your counts.
When sewing pieces together, use the yarn tail left from fastening off rather than cutting a new length. This keeps the attachment point secure and eliminates one extra end to weave in.
About the PDF Download
The downloadable PDF version of this pattern includes the full written instructions with stitch counts, a materials list, a notes section for customization tips, and a visual stitch guide for anyone who prefers a diagrammatic reference alongside the written instructions. The PDF is formatted for easy printing on standard letter or A4 paper and is sized with crochet-friendly fonts so you can read it on a tablet or phone without zooming.
The PDF is available for instant download after purchase. Once it’s in your files, it’s yours to print as many times as you need, share with your own crochet circle (for personal use), and annotate with your own notes and modifications. Many crafters print a copy for their pattern binder and keep the digital version on a tablet for easy studio reference.
Whether you’re making these to sell at craft markets, adding them to handmade gift sets, or simply building a little menagerie of monsters to hang from every bag you own, this pattern is designed to be used, loved, and made over and over again with satisfying results every single time.
If you’ve worked your way through this tutorial, you now have a complete, fully customizable kawaii amigurumi monster keychain to show for it — big mouth, wide eyes, questionable number of teeth, and all the personality you stitched into it. These little creatures have a way of becoming beloved almost immediately, both by the people who make them and by the people lucky enough to receive them. Happy crocheting.
