I am a word of 12 alphabets.
* Alphabets 12, 4, 7, 2, 5 : Eastern beast of burden
* Alphabets 1, 8, 10, 9 are street made famous by Sinclair Lewis.
* Alphabets 11, 3, 6 are past.
On whole it means a person suffering from delusions of greatness.
What Is it ?
megalomaniac. (Camel , Main and Ago)