Puzzle ZYJF 

Workings

Hint
A very common sequence is hidden here.

Answer
Badger.

Reasoning
The length of the words is the same length as the months of the year.
   gorilla  = 7 = January
   hedgehog = 8 = February
   camel    = 5 = March
   mouse    = 5 = April
   fox      = 3 = May
   bear     = 4 = June
   mole     = 4 = July
   badger   = 6 = August