Well, with basically no arms or legs to speak of, just having hands and feet attached directly to the body, it's going nowhere fast. In fact, it can barely move.
In addition, it's massive jaw muscles for such a huge mouth would probably take up so much space that not all the other needed muscles and organs could fit in the body.
Even if it could somehow squeeze in all the necessary organs, it can barely move.
If we assuming it's an herbivore, and thus does not need to chase prey, it's unarmored hands and feet are basically free snacks for whatever predator finds this thing first. It can't defend itself in any meaningful way.
And all of this is assuming it's not just a living rock, which would require magic.
For this creature to be viable, it would require so many changes, that it would scarcely be recognizable.
The body would need to be much larger, to actually fit in all of it's organs.
It would need arms and legs so that it can actually use those hands and feet.
realistically speaking, it would also need either a neck or snail-like stalk eyes so that it can look around without moving it's entire body.
If I were to re-design this monster, it might look something like this:
(Apologies for the crude drawing, I didn't spend a ton of time on it.)
A few notes on this design:
- It now has arms and legs, so it can effectively move around.
- It's eyestalks let it look around without moving it's entire body; useful to save energy and make less noise.
- It is not made of rock; it has hard, armored scales that look like rock.
- Even though it can move now, it's probably still not very fast. It's most likely an herbivore or scavenger that relies on armor for defense.
- I noticed that the monster does not have opposable thumbs. This isn't strictly a problem; raccoons do not have opposable thumbs, and yet their paws are still quite dexterous. It will not have the same level of finesse as us humans, though.
- Hitting itself on the head to create a drum sound isn't out of the realm of possibility. It might have a hollow resonating chamber in it's head; striking itself on the head is a means of communication between others of it's kind.
- I imagine it lives somewhat like an armored gorilla. It probably lives in groups, since it has a unique structure for communication, and since it's most likely an herbivore, it will spend most of it's waking hours eating.
- It might be able to pick up sticks and use them as clubs to whack predators with. If I were a lion, and I ran into a bunch of these things waving sticks at me and hitting themselves on the head, making a loud drum sound, I would be rather intimidated.