First, turn your sock inside out and flatten it out with the heel facing downwards.
If forgot to turn it, so the sock I am demonstrating has the wrong side out.

Draw the shape of the ears on the top. This is a 25 cm long sock, and the ears I drew are 6 cm long.

Sew along the line and cut away the middle part.

Time to stuff your Totoro. I used the filling of an old pillow. It is easy to shape.

Stuff it til it is semi-hard and shape-able. Leave some fabric in the bottom.

Cut that part of and save it. Spare a little for seamallowance.

And now we make that famous little butt. Fold the fabric inside

Start sewing from inside the folded part. Insert the needle in all the little wrinkles in the fabric.

Hopefully it will end up looking like this. The first one looks better, I hurried trough this time.

The tail is made from the spare piece of sock you cut off earlier.

Sew around it, but leave the end open. Stuff the tail and close it.

Attach it to the back of the Totoro. Some how one of the sides looks more like a back than the others. If not, it can be shaped.

Cut out eyes, nose, and belly in black and white felt. I just handdrew the pieces. If making the smallest Totoro, you only need to make eyes.

Glue the felt on. If it is for smaller children, you might want to sew it on.

I shaped the ears of the largest Totoro, with thread through the bottom of it's ears.

Make sure you sew it tightly enough, so the thread is not visible.

And you're done!