Lachesis
I've noticed quite a few different User Agents recently from a IP addresses that point to sites, or a site, protected by HT Access where the 401 message always feature the word 'cerberus'.
In Greek mythology Lachesis is The Disposer, one of the three Erinyes (Fates). She measures the length of the thread of human life spun by Clotho and determines its destiny.
More digging required...
status : not blocked
First noticed : 2002-10-08
earliest IP address : 138.15.164.9