Insanely ugly woman, having the characteristics of all or any of the animals involved in the word, be it Hippo, Crocodile, Dog, or Pig.
Someone who qualifies as a real hippocrocadogapig is not someone you would want to have sex with in a hurry. A real ten pinter.
Credit for this to Gail, it's been a useful word all too often since I learnt it.
Whoa, shit man, look at that hippocrocadogapig over there, but for god's sake don't get caught looking.