|Left Shark is the one to the...left. Image from NYMag.com.
Presumably using some sort of mutagenic ooze, or perhaps an advanced form of radiation treatment, Perry procured two bipedal, dancing sharks to be part of her crew. And by the next day, one of them had stolen the internet. The shark on the viewer's left - who has since become widely known as "Left Shark" - performed some goofy choreography (perhaps non-choreography?) that really captured our hearts that night.
Here's part of the performance in question which includes the key moves (it is worth checking out the full peformance, though; all of her dancing stuff is pretty funny):
I'm pretty sure.
Anyway, this post is especially timely, as the dancer in question (presumably de-mutated at some point following the show), Bryan Gaw, has finally begun talking about that night. Here's the piece from NPR where he explains that the goofiness was all part of the plan. And if that's really the case...well, I'd say it worked pretty darn well!
Seriously, watch the sharks dance. Puts me in a good mood every time.