Poor, confused Brother Warth - he's an elephant, and elephants are afraid of mice. He's also a Blue Lantern, and so he knows that the Yellow Lanterns (aka the Sinestro Corps) are all capable of inspiring great fear; can you blame him for being untrusting?
His second line is a reference to the belief, commonly held by the world's stupidest criminals, that an undercover police officer must identify himself as such if asked directly. Why do they believe this? Because they're stupid, of course. If a cop's undercover and someone asks him if he's a cop, he can lie right to their stupid face. So don't count on that keeping you out of trouble, wannabe teenage rebels.
Mickey Mouse, of course, is the symbol of the Walt Disney Corporation - and Disney owns Marvel, so of course that's the comic company he'd know.