Board Thread:False Info and Speculative Discussion/@comment-27698266-20160328060519/@comment-26879545-20160328175711

It's hard to rely on mythology for this, but generally the lesser hellhounds work in groups. Cerberus is said to be the guardian of the Underworld and as such, is usually by his lonesome and left to do his guardian duties. Hellhounds like Black Shuck are said to just wander around and those who see it are said to have an imminent death.

In TW, it's possible the Hellhound has a pack, but as this particular Hellhound identified himself as Cerberus and Black Shuck (and Garmr or whatever), it's possible he works alone.