We're not sure what a Pinger is, but according to this trailer for Crysis 2 it's supposed to attack during E3. Does it make "ping" sounds? Or, as one of our co-workers asked, does it check for your latency using its lasers? We just don't know.
It doesn't help that the 50 second trailer below consists of 10 seconds actual footage and 40 seconds of logos and taglines. But if that's your poison, or you just can't get enough of Crysis 2, enjoy!