Cynocephalus (pl: Cynocephaly[1]) or Doghead[2] is a humanoid creature that resembles a dog-headed monkey.[1] They are social creatures and live in packs, making them particularly dangerous to deal with.
They live in dark, underground areas such as mines[1] and in the wastes of Zangvebar.[2]
According to Gnomish Prankings, a cynocephalus urinates at the toll of each hour and thus Zangvebarians engrave the creature on clocks and compasses.[2] It's hard to say if this is true or not due to the book's nature being about pranks.