Aspect of the spider service

Is there a place to ask for this? Need it on my hat.
Also is give items to people common practice and safe?

Or can I buy this beast on the market?

Yes, assuming there are any for sale, you can buy an itemized one.

You're looking for "Fenumus, First of the Night" unique itemized beast.

Technically there's also "Fenumal Hybrid Arachnid" (which is the beast that lets you fight and capture Fenumus), but Fenumus is probably cheaper.

Yep, I bought the hybrid and did it myself.