Those appeal. Added to
Homebrews.
I would make the bite the primary attack then fiddle the strength bonus from Enlarge so its claws do 1d6+2 when embiggened (which would require a Str of 18-21).
That would mean a regular-sized Weisshund would have 1d4 claws, I'd set the bite to 1d8 like a Hell Hound.
Now the enlarge power seems to be its most important ability.
Reading the description it's a slightly less potent ability than
righteous might since it doesn't give the DR or AC boost. How about.
Enlarge (Su): A weisshund can enlarge itself as a swift action. This increase changes the Weisshund's size category to Large and gives it a +4 size bonus to Strength and a +1 enhancement bonus to natural armor, changing its statistics as given below. Any equipment the weisshund is wearing is similarly enlarged by this power.
Large Magical Beast
Hit Dice: 4d10+16 (38 hp)
Initiative: +2
Speed: 50 ft. (10 squares)
Armor Class: 16 (-1 size, +2 Dex, +5 natural), touch 11, flat-footed 14
Base Attack/Grapple: +4/+13
Attack: bite +8 melee (2d6+5)
Full Attack: Bite +8 melee (2d6+5) and 2 claws +3 melee (1d6+2)
Space/Reach: 10 ft./5 ft.
Special Attacks: Enlarge, improved grab
Special Qualities: Darkvision 60 ft., detect hostile intent, low-light vision
Saves: Fort +8, Ref +6, Will +3
Abilities: Str 21, Dex 14, Con 19, Int 8, Wis 14, Cha 11