Talking of ping quirks.

If you have a IP address with more than one PTR on it's reverse DNS like so:

$ dig -x x::6969 +short
hoho.b621.net.
haha.b621.net.
hehe.b621.net.

If you ping it (on seemingly older versions of ping) it will pick a random PTR to display per ping.

Resulting in amusing displays like:

# ping hehe.b621.net
PING hehe.b621.net(haha.b621.net (x::6969)) 56 data bytes
64 bytes from haha.b621.net (x::6969): icmp_seq=1 ttl=64 time=0.094 ms
64 bytes from hoho.b621.net (x::6969): icmp_seq=2 ttl=64 time=0.104 ms
64 bytes from hehe.b621.net (x::6969): icmp_seq=3 ttl=64 time=0.110 ms
64 bytes from hehe.b621.net (x::6969): icmp_seq=4 ttl=64 time=0.136 ms
64 bytes from hoho.b621.net (x::6969): icmp_seq=5 ttl=64 time=0.132 ms
^C
--- hehe.b621.net ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4075ms
rtt min/avg/max/mdev = 0.094/0.115/0.136/0.016 ms

This was noticed because for some reason, one of Google's net infra IPs has 3 different PTRs, in two different city metros

$ dig -x 216.58.201.110 +short
prg03s02-in-f110.1e100.net.
prg03s02-in-f14.1e100.net.
lhr48s48-in-f14.1e100.net.