This is a "plushie" design, made "in the hoop" on an embroidery machine. It produces a larger-than-your-hoop octopus that you can keep, gift, or sell.
It can be made in a 4x4 (100mm) or larger hoop. It will produce an octopus with a leg-span double that of your hoop's shorter dimension, or that of your hoop's longer dimension - e.g. 5x7 hoops can make either 7x7 or 10x10 octos. The magma octopus is 7x7, while the leopard is 8x8 from a 4x4 hoop.
The only hand-sewing is ladder-stitching a single turning opening.
"Plush" is a bit of a misnomer - this pattern won't work in pile fabrics except at very large sizes, but instead requires swim/dance fabric.
The files come in all the formats Ink/Stitch can produce, along with the SVG source file that you can edit in Inkscape+Ink/Stitch. There is a step-by-step PDF that includes full instructions, including a picture of every stitch color step. and multiple pictures of trimming and turning.
You can make plushies to sell, and I highly encourage it.
Make an in-the-hoop octopus four times the size of your hoop.