Sherlock was well-known enough in his own world for him not to be too taken aback at that statement. He'd heard it before. But, it was something of note that this was coming from someone not of his world. Unless he spoke to Helen in the meantime...?

"Yes, the Sherlock Holmes," he furrowed his brows, the annoyance clearly in his tone. Just because he looked like a lizard...did he have to prove it to him, or something? He didn't like the way he said 'greatest detective,' he'd been mocked too many times to take it at face value. His eyes narrowed.

"Yes. All that stuff. I can read your history in your clothes and in your shoes, in the way you carry yourself and in your choice of words. Anything I would say could be easily brushed off if you suspect that Helen Magnus has told me, however you could easily ask her yourself. And I can assure you she will tell you that I am telling the truth." Sherlock leaned closer, his forked tongue flicking out in a slightly aggressive manner. "I am the world's greatest detective." At least, in his world.