Answer:
Looks like water, but it's heat. Sits on sand, lays on concrete. A play on the eyes, but it's all lies.
Has no feet, but travels far. Is literate, but not a scholar. Has no mouth, yet clearly speaks.
It is able to speak because it has a hard gone. You know what it is as soon as it has sung. What is it?
Snake coiled round and round. Snake deep below the ground. Snake that's never had a head. Snake that binds but not with dread.
It is the electronic version of junk mail or a salty meat in a can.
Those with eyes bigger than their stomach will definitely leave the restaurant with one of them. It is named after a house pet as well.