OK, so Old Bonegrinder the warthog has 7 HD. Playing LoF with PF characters, it seemed reasonable to give him another feat; I chose Powerful Charge (+2d6 damage on a successful charge). This was a mistake.
The party's scout detected him early, and party tactics were good: the Barbarian 1/Sha'ir 2 and Fighter 3 got into poision on either side of the opening to the hog's lair; the Scout 1/Cleric 2 (archer) and Rogue 3 would fire bows at him, hoping to get him into position between the flankers, who could take 5-ft. steps forward and chop him up.
Alas, Bonegrinder easily passed his Perception roll to hear them, won intiative, and charged the scout (passing both melee guys before they could react), killing him in one shot. The rogue fired his crossbow while the Sha'ir advanced and the fighter threw a javelin and moved forward; Bonegrinder charged and killed the rogue. The other two attacked him in melee, and Bonegrinder couldn't miss (+12 attack against the fighter's AC 22 wasn't all that hard), and quickly killed the two of them; scene ends with warthog tossing bloody corpses all over the road and gnolls (attracted by the commotion) laughing like the hyenas they are.
Bottom line: if you "soup up" Bonegrinder, even a little bit, make sure that he loses initiative.
I am running the module for two different groups, and the first group had no idea Bonegrinder was in there and ran out to attack the gnolls that were bringing him food, and they ended up against 4 gnolls and Bonegrinder at level 2. They got captured by the gnolls and thrown in prison, where they had to go through the ordeal of being tortured by the Ogre until they were able to escape with the aid of Haleen. In the other group they confronted bonegrinder, and they realised they were in over their head and they all hauled ass back to camp thanks to the barbarian's speed and the magic users expeditious retreat spells they had prepared. They later came back with spears borrowed from Almah's troops and set for Bonegrinder's charge.
Perhaps upping the Con until it has one more +1 bonus and if you give it another feat perhaps give it the Toughness feat instead?