You need:

Approx 25g yarn (dk if possible, but scrap yarn will do) and hook to match yarn (between 3mm and 5mm) 

A small amount of stuffing (optional) 

Basic crochet knowledge! Instructions are in US terminology so make sure you’re familiar with the differences from non-US terms especially the stitch names.

Instructions:

Ch 4 and slip stitch together to form a ring, or start with a Magic circle.

Single crochet 8 times into the ring. (8sts) 

You can add a stitch marker into your last stitch here, or use a large piece of yarn of a contrasting colour. 

Increase every stitch, working 2 sc into each st until you have 16 stitches. (16) 

Increase every 2^nd st working 1 sc into the next st, and then 2sc into the next st. Repeat around until you have 24sts (24) 

Single crochet into each st around for 4 rows ie 24 stitches for 4 rows for a total of 96 sts(96) 

Single crochet into the next st, then combine the next 2 sts to decrease, by inserting your hook into the 2nd sc, yarn over and pull up a loop, leaving the two loops on your hook, insert your hook into the 3rd stitch, yarn over and pull up a loop, you should now have 3 loops on your hook, yarn over and pull thru all 3 loops. Repeat 7 more times. (16) 

Single crochet decrease every stitch around (8) (Now is the time to stuff your Octo). 

Single crochet in each st around in the back loops only. We will be using the front loops to make the tentacles. Fasten off your yarn, and tighten.(8) 

Making the tentacles 

[You can do pretty much anything you want with the tentacles; it’s essentially just eyeballing it and deciding if it’s looking how you want it to look and adjust as desired. If you want longer tentacles,

add more chain stitches. If you want them shorter, do less chain stitches. If you want them curlier, do more stitches with increases, if you want them less curly do more regular stitches between increases. The tentacles are a great way to add individuality to your octopi! You can do literally anything you want!] 

Attach your yarn in any stitch you like. Ch 12 + 2 (14) Work 3 sc into the first st, then one sc into each of the next 2 stitches. Repeat to the end, sc into the starting st and then into the front loop of the next Octo stitch, as if you were working a decrease, and ch another 12 + 2 for your next tentacle, and repeat, until you have eight tentacles. Fasten off and weave in your ends.

Attach whatever eyes you’re using, either safety eyes, or buttons, or make crochet eyes by making a mc and working 8hc into it, pulling closed and slip stitching to join, with a 2.25mm hook. 

You can put a little bit of stuffing into your Octopal if you wish. Old socks make a great alternative for stuffing. You can then close the opening with some yarn and a darning needle.