I'm having a deja vu attack - have I previously posted about Ronald Chetwynd-Hayes? Fantastic, horribly under-rated author, sadly now deceased. Many of his books and stories featured a group of dog-headed men, called 'The Pack'. They never speak and dress like MIB, travelling round in 'large black, box-like' car. Generally, they are in the employ of sinister conspiracies, acting as enforcers against those who have seen too much.
Funny thing about RCH; his writing is obviously taking the piss most of the time. Yet somehow, it has an oddly convincing edge. Since we now have dozens of sitings of Dog-Headed-Dudes here, I wish to make it plain that 'The Pack' are fictional and I in no way believe in their literal existence.
Woof.