The mystery deepens: who is blue shark?

Fo some time now, there has been a mysterious visitor to this blog - blue shark. Tantalizing tidbits have intermittently appeared, promising blue shark's imminent arrival.

Well, today, blue shark arrived. Or more accurately, his picture. How did he ever get my mailing address?

And more importantly, who is blue shark?

The envelope betrays nothing except a Vermont postmark.

Stalin is perplexed. And expectant. And excited - I mean, I got fan mail! Hooray!

So, blue shark: Stalin awaits more. Are you perhaps.... interested in mating? We could have an entire school of cute little sharklets - think about it.