I've made Horace the hermit crab using Aran/worsted weight yarn. I used a tweed yarn for the shell, but you can use any tweed mix/variegated/print yarn to give it a lovely "shell" look.

The pattern is clear to follow with detailed instructions and lots of pictures for step by step making and assembly. There are also picture instructions for front post stitch and back loop only.

I've made Horace using Aran/worsted weight yarn and a 4mm (G) crochet hook. He is 6.5 inches long and the shell is 5 inches tall.

The following stitches/techniques are used in this pattern: slip stitch, single crochet, front post single crochet, increase, decrease (sc2tog), back loop only

(This pattern is for personal use only, not to be resold or rewritten in any way. I am happy for you to sell the finished toy, but please credit the design to me.)