Crayfish, actually, and only related to the lobsters — but a little B-52s reference does get the Sunday morning heart a-pumping.
With the camera flash, this fearless crawdaddy sure does look like a cooked lobster. When it saw me, it reared up, all three inches of it, to let me know that it was a bad-ass who wasn’t gonna give an inch of ground.
More than a dozen species of crayfish have been discovered in the fresh waters of New York state. This looks like the invasive southern swamp crayfish, known by many other names including the Louisiana mudbug. Another word for them is delicious. Your Classicist would call it a Procambarus clarkii. Prospect Park is, alas, a magnet for invasive species.
As an aside, I’ve found actual lobster along the East River, most likely sucked down that turbulent tidal channel from Long Island Sound.