Most of us crocheters have made or want to make amigurumis. I've made several cats and dogs and some other creatures in the past. I observed in Ravelry that it is mostly made from worsted weight yarn, or even thicker yarn. Though there are Japanese amigurumi patterns that are made from light fingering (3-ply or 4-ply) yarn. For this we can substitute Cannon threads.
I've used our local threads for many amigurumi projects, sometimes I double or triple the strands and use from 2.5mm to 4mm hook.
Below are two of my latest projects and I used 2.5mm hook and one strand of Cannon thread. It may seem tedious, but crocheting with size 8 thread is very easy on the hands.
These cats are referred to as Lucky Cats, and we made it our Crochet-along project in our Ravelry group. The other cats we made can be seen here in my main blog ;)