Wet the mink so he is sopping wet, and put him in a sealed plastic bag and freeze him...he will last for a long time that way. Ive been told Im wrong, the water will harm it. I usually ask why it lives in water, then? Being that wet when freezing helps it not dry out, of course.

Get in touch with a good taxidermist who knows well how to degrease AND descent the mink, remember, hes a mustelid, like a skunk. A very popular mount out of my studio is to mount him in a glass case on snow, at the waters edge, with ice, cattails and a small fish at his feet. I spike its hair with an acrylic to make it appear wet. Your taxidermist probably has some decent ideas as well. Good luck, and dont tell people you shot it.