I don't remember if we got them at the Boardwalk Villas, but I distinctly remember getting them at the Wildnerness lodge, and we never tipped. We had the same mousekeeper every day, and she was wonderful. I was with 2 girlfriends of mine and all of our
bath and bodyworks girly stuff. I remember she made comment of how wonderful our room smelled, and she would leave us tons of mickey soaps and stuff each day, and would always arrange our stuff very nice on the vanity. As to the towel animals we got a few, but what was more fun was how she'd arrange our souveniers each day on our be, on the balcony, on the tv etc. She was great. All we really did was say hi to her in the hallway each day. Of course we left her a tip on our last day.
At the the villas, we had a suite with an adjoining room, I'm sure we had something, but it wasn't nearly as memorable. I think its just a hit or miss thing, but I would never purposely pay for them. We went on a
Royal Caribbean Cruise for our honeymoon and we got at least one a day, if not more and our cabin steward even taught us how to make one, they are fun, and we never took them apart, we had a virtual zoo in our room after 7 days, but they certainly worth stressing over. Don't let it make or break your vacation. There are much more magical things at disney than a towel animal.