Dumb question: Are you sure you HAVE the quest??
The beast doesn't show up until you have the quest! (think you also need to find the writ too - gads, my memory is going!
)
I always found him inbetween the route to the Stout Mines and the entrance to Dragon Spire. He often showed up in the same areas that you find Jathil.
Good Luck!!
Wyv