You might be wondering what makes this the safest fingerprint in the world? Well, have you ever tried to grab a hedgehog that doesn't belong to you and force it to do something? That's going to be painful.
I suppose there are even safer options. Maybe you could enroll the paw of a full grown porcupine instead, or maybe a tiger or something. Maybe the hedgehog isn't the safest option, but it's a good balance between safety and convenience.