Stress
Not much if it's a hobby, probably more if you are trying to start a business.
If you pursue taxidermy as a hobby, it's a good way to relax by losing yourself in a solitary pursuit. Start building a business or entering a competition, and you'll start to feel the adrenaline.
Customers also have a way of demanding more than you bargained for: chit-chat time, unreasonable expectations, or messy carcasses that don't pay much but mean a lot of stitching and patching. You'll have to invest in supplies and practice a lot, which takes time. If you don't have supplies on hand, who pays for them and how do you get them shipped to your old shack in Oklahoma with no street address in time for the hunter's birthday?