Trying to find a novel about a group of humans stranded on a planet with shapeshifting aliens. There was another human stranded on the planet before this group arrived. This person taught the aliens to keep a child-like humanoid shape so any other humans they met would think they were cute and wouldn't hurt them, but their real shape was something like a spider. I think the author was fairly well-known.
Nevermind, I found it. It is Life Form by Alan Dean Foster.
Foster presents a spellbinding odyssey of a planet miraculously like Earth. Until close observation shows that on this world, nothing is as it seems. Welcome to Xica, where nine scientists from Earth have established first contact with a humanoid civilization. Now all they have to do is live to tell about it. From the author of Greenthieves.