wdns is a simple DNS relay server that can do wildcard DNS for IP Addresses. Like xip.io, but with a small change. This supports hyphens in addition to dots.
When run with
int.example.com as argument, it will resolve
192-168-1-1.int.example.com to 192.168.1.1 192.168.1.1.int.example.com to 192.168.1.1 foo.10-1-2-3.int.example.com to 10.1.2.3
This supports only requests for A records (for wild card DNS), and any domain that's doesn't match *.int.example.com gets resolved as per Google DNS Server 22.214.171.124