Those are all kinda weak. When you look at the natural attacks that other Vestiges grant, they each have some kind of special ability. Extra damage when charging, pounce, cold iron, etc.
Both Lizardfolk and Vampires are known for their bite attacks; let's grant one of those. It's better than claws, since most times you want to hit with a weapon in your hands.
Jaws of the Vampire -- You gain a bite attack (1d4/1d6 for small/medium) as a primary or secondary natural attack; if you already have a bite attack, naturally or otherwise, you may instead choose to increase the damage of your other bite attack by two size categories. If your EBL is at least 11, your bite is considered Silver. If your EBL is at least 15, your bite is considered Silver and Lawful. You do not gain this benefit if you do not show Sakatha's sign.
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Vampires and Lizardfolk both have tough skin. Let's give some Natural Armor and DR.
Scaly Ward -- You gain a Natural Armor bonus equal to one-half your Constitution bonus (rounded down), and DR/silver equal to one-half your Charisma bonus (rounded down).
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Vampires are known for their gaseous form; Lizardfolk are known living in misty swamps. Hmm. Something with mist?
Alternately, your command scaly critters ability looks good. Something like...
Scaly King's Command -- Once every five rounds, you may use an effect similar to
command on any reptile (if the reptile does not understand any language, then this ability is not [Language-Dependant]).
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And something for the King...
Aura of Majesty -- You may project an aura out to 30 ft., which affects yourself and all allies. You may project one aura at a time. Switching auras is a Swift action. You can not project an aura if you do not show Sakatha's sign. Your available auras depend on your EBL:
- (EBL any) -- Aura of Sakatha's Victory: +2 melee damage against mammals.
- (EBL 5+) -- Aura of Sakatha's Domain: +8 to Swim checks.
- (EBL 9+) -- Aura of Sakatha's Resolve: +2 to Will saves.
- (EBL 13+) -- Aura of Sakatha's Immunity: energy resistance 10 vs. cold and electricity.
Cheers, -- N