I have just started a Scarred Lands campaign (The Serpent Amphora Cycle), and while I think SL is a top notch setting, IMHO some of the monsters from CCI are in need of a rewrite. Here is my take on the Hill Howler, as it might be of interest to some of you.
The most notable difference is that I changed the Terrifying Howl from an Ex to a Su ability, since other creatures with similar abilities (Shadow Mastiff and Yeth Yound for example) define them as Su. The addition of a Su ability changed the Hill Howler's designation from Beast to Magical Beast.
Hill Howler
Large (Tall) Magical Beast
Hit Dice: 4d10+16 (44 hp)
Initiative: +3 (Dex)
Speed: 45 ft., climb 15 ft.
AC: 15 (-1 size, +3 Dex, +3 natural)
Attacks: Bite +7 melee and 2 claws +2 melee
Damage: bite 1d8+4; claw 1d6+2
Face/Reach: 5 ft. by 5 ft./10 ft.
Special Attacks: Terrifying howl
Special Qualities: Darkvision 90 ft., low light vision, scent
Saves: Fort +8; Ref +7; Will +1
Abilities: Str 18, Dex 16, Con 18, Int 5, Wis 10, Cha 5
Skills: Climb +8, Listen +4, Move Silently +7, Spot +4
Feats: Alertness
Climate/Terrain: Temperate foothills
Organization: Solitary
Challenge Rating: 3 or 4?
Treasure: Standard
Alignment: Always chaotic evil
Advancement: 4-8 HD
Darkvision (Ex): The hill howler possesses darkvision at a range of 90 ft.
Low Light Vision (Ex): As with most magical beasts, the hill howler possesses low light vision.
Terrifying Howl (Su): All within a 300 ft. spread must make a Willpower save (DC 16) or be shaken for 2d4
rounds.