"They tolerate you, Odo, because you emulate them. What higher flattery is there? I, who can be anything, choose to be like you. But even when you make yourself in their image, they know you are not truly one of them. They know that what you appear to be does not reflect what you really are. It's only a mask. What lies underneath is alien to them, and so they fear it. And that fear can turn to hate in the blink of an eye."
:DS9: "Chimera"