The first ten or so lines of ping 1.2.3.4 are not output immediately, but appear all at once after the delay associated with that many pings. Each next line comes out individually as before.
Ping is reverse-resolving the IP of the host you're pinging so that it will show up in the result. You won't see this behavior if you ping the same machine again, and there's a switch to turn it off.
*** This bug has been marked as a duplicate of 10436 ***