If you are not able to cruise and learn the art though, there is a solution--how-to books. Three of them pop up in an Amazon search: Carnival Towel Creations (published by Carnival Cruises of course), Towel Folding 101, and How To Make A Towel Monkey And Other Cruise Ship Favorites.
Imagine the look on the face of your family and/or friends when you host them overnight for the holidays and on their bed they find a clever towel animal. Just be careful though. They may begin to expect the other amenities that come with cruising like room service.
While we've enjoyed hanging monkeys, lobsters and bunnies with sunglasses (ours) on the bed, the most unusual towel creation however was a full body on the bed. Yup. Towel arms and legs, my sandals for the feet, a shawl wrap, and a straw hat sitting just above eyeglasses. I almost screamed when I opened the door to our room but luckily realized it was all towels and not a stranger in our bed.
There is always an interesting discussion on the Cruise Critic and there is an article on their blog that talks about towel creatures and the author's attempt to create them.
For me, I'll just continue to be amused by the efforts of others.