With the hippogryph lore adittion it come to my mind the idea of a Monster Book or Bestiary and that we can made it together, it's simple, we have to put:
Monster/Creep/Animal name (cientific names can be added but common names are preferable)
Length
Hostile/neutral/friendly/tameable
Habitat
A brief description from our own
A picture
Skull Crab
20-30cm from side o to side 50 with the legs extended
Neutral (it prefers fleeing, only fights back if it feels cornered)
Found mostly in swamps and caves with great humidity
It was believed time ago that these crab didn't have a shell of its own, so they look for human skulls for protection, it was later know, thanks to captivity study that the shell actually is shaped in form of a human skull, probably for camouflage purpose, the moss that sometimes grows in the skull is toxic and can be distilled in a powerful sleeping brew