Clearly, these are white dire wolves and not intelligent creatures that would be insulted by his growl.
Dismount and move to S-16 (he has 35 ft movement in Medium armor now thanks to the fast movement of Berserk).
A couple notes:
1. He is raging (only), so the below stats apply.
2. He wears Steadfast Boots(MIC 138) which state "As long as you carry a two-handed weapon, you are treated as if you had readied that weapon against any creature that charges you."
His Guisarme is a two-handed weapon.
It also provides a +4 bonus against being tripped, so with Jotunbrud (+4) and Wolf Berserker (+4) and a +5 Strength bonus while raging...effective +17 Strength mod for resisting trips, in case the winter wolves go less 'winter' and more 'wolf' on their attacks.
Medium Humanoid
Hit Dice: 6d12+30 (90 hp)
Initiative: +2
Speed: 35 ft (50 ft in no armor)
Armor Class: 16 Touch: 10 Flat-footed: 14
Base Attack/Grapple: +6/+15
Attack: +1 Guisarme +12 (2d4+8) or Trip +12 (+17 on check)
Full Attack: +1 Guisarme +12 (2d4+8) or Trip +12 (+17 on check)
Space/Reach: 5 ft/5 ft (10 ft with Guisarme)
Special Qualities: Fast Movement, Trapfinding, Evasion, Trap Sense+1, Uncanny Dodge, Movement Bonus
Saves: Fort +12, Ref +7, Will +6
Abilities: Str 21 Dex 14 Con 20 Int 10 Wis 14 Cha 10
Skills(*ACP = -4 included): Balance* +5, Intimidate +8, Jump* +11, Listen +11, Move Silently* +5, Search +6, Sense Motive +8, Spot +11, Survival +11(+13 while tracking), Tumble* +8
Feats: Feats: Feats: 1 - Jotunbrud(1), Wolf Berserker(H), Power Attack(FR1), Improved Trip(Totem), Knock-Down(FR2), Combat Reflexes(3), Improved Bull Rush (FR4), Track(Totem), Righteous Wrath (BoED), Leap Attack (Fighter 1)
Environment: Berserker Lodge or Adventuring Party
Organization: Individual(Unique) or Adventuring Party(self plus 3-5 other PCs) or Wolf Fang(self plus a group of wolf berserkers)
Challenge Rating: 6
Alignment: Neutral Good
Languages Spoken: Common(Rashemi)
Level Adjustment: +0