Lithotrophy is a phenomenon known from microscopic life, where an organism converts inorganic substances, usually minerals, into energy.
So, we know that a single-celled life form can do this, but what about a more complex one? Could a macroscopic, motile, animal-like organism feed on minerals, like iron or sulfur, and if so, how would it work?
I am asking this question for use in the construction of an alien planet, with which I want to break the trend of Earth-like aliens seen in most popular movies and books featuring complex extraterrestrial life.
The organism(s) in question shall be as large as humans or bigger, have multiple legs, and hard endoskeletons. The reason I'm asking this question is a) I'm not a biochemist, b) this phenomenon has never been observed in macrofauna, and c) I can assume that it would bring a host of side-effects and possible ramifications.
In an answer, I'm hoping for a "yes" or a "no", to indicate whether it's possible, and then hopefully a few words on things like digestion, biochemistry or any other things I need to know to understand how the organism works, not just know what it does.
Please note that I have had a look at the question Can anything survive by eating rocks and other ground minerals? and it does not answer my question. It asks if there are any real-life lithotrophs, which I know and made clear in the first sentence of the question. It does not proceed into the realms of speculation which I'm looking to enter, and the OP also does not want to understand how this phenomenon would work.