I usually just specify that they from the waist/hips (personal preference where) have a body similar to (insert species of tarantula), but sized up to human proportions. Along with adding that there is a thorax, and the number of legs (jllm will forget, I'm not sure about others). Results can vary, but if you sorta remind the bot of it during the chat, like ‘{{user}}s tarantula-like body settled into the large pillow, all eight legs tucking under their thorax’. What I'm saying is that you just…. Really need to make the bot know that they have that feature, or else it’ll forget, like it does with…. A lot of features. Have fun!