Terrapede

The Terrapede is a giant centipede made out of rock.  Each of their segments is bigger than a house, and they'll sometimes walk through cities by sheer accident, not noticing the wreck they caused.
The reason for this is that they have no eyes, and their brains command them to always walk forward.  As a result they do exactly that, sometimes burrowing through mountains, forming a brand new cave system, other times burrowing through the ground if it's too soft to support their weight, also forming a new cave system. Sometimes they'll walk straight into a lake or the ocean, often drowning in the process.
The only reason they're not extinct is because they're too hard to kill, and their constant diet rocks keeps them full, and they reproduce whenever a piece of them falls off and turns into a new Terrapede.
Intelligence was therefore never selected for by evolution.
Thank you to Ragdoll for suggesting the name!