The word for this thing is “pareidolia”. It refers to those situations when one thing looks like something completely different. Normally, people use it when seeing faces in clouds, but it applies to lots of different kinds of misidentification too. If a rock looks like a house, that’s also pareidolia.
I know of pareidolia, actually a few of these I got them from r/pareidolia (when reddit wasnt as shitty), but looking up "trollface pareidolia" wouldn't get me any significant source for them.