How about getting him a taxidermy class or workshop as a gift? This way, he can learn more about the craft and hone his skills. Or, if he already has a lot of taxidermy pieces at home, you could consider getting him a book on the history or techniques of taxidermy. Another option could be to get him a custom-made taxidermy piece of his favorite animal or a unique piece he doesn't have yet. Just make sure to do your research and find a reputable taxidermist for this option.
Or you can get him a star map with the date when he was born.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.