A person with many layers like an onion or an ogre (hence the name Shrek). Their personality is convoluted, confusing and multi-faceted. To understand them, one would need to refer to a mental psychologist.
Shreks are funny and make good conversationalists. They appear to be overly confident (just a defense mechanism), believe that no one truly knows them (again, just a self-preservation technique), smoke too much Shisha, and make great reliable friends.
They are very creative but need to learn to admit when they lose arguments to others. They don't know how to give compliments and drive like a maniac but overall have a heart of gold!
Can you speak clearly and stop being such a Shrek? Just saying...