Mantidrake
Ok, here's the evolving Mantidrake statblock:
Mantidrake
Huge Dragon
Hit Dice: 10d12+70
Initiative: +1
Speed: 30 ft (6 squares), fly 60 ft (clumsy)
Armor Class: 21 (-2 size, +1 Dex, +12 natural), touch 9, flat-footed 20
Base Attack/Grapple: +10/+27
Attack: Claw +20 melee (1d8+12) or 6 spikes +11 ranged (1d8+6/19-20)
Full Attack: 2 claws +20 melee (1d8+12) and bite +18 melee (2d6+6); or 6 spikes +11 ranged (1d8+6/19-20)
Space/Reach: 15 ft./10 ft.
Special Attacks: Spikes, Breath Weapon
Special Qualities: Darkvision 60 ft., low-light vision, scent, immunity to sleep, paralysis effects, and energy (see below)
Saves: Fort +14, Ref +8, Will +9
Abilities: Str 34, Dex 13, Con 25, Int 7, Wis 14, Cha 11
Skills: Hide -7, Listen +15, Spot +19, Survival +15, Intimidate +13
Feats: Flyby Attack, Multiattack, TrackB, Weapon Focus (spikes), Snatch
Environment:
Organization: Solitary
Challenge Rating: 10
Treasure: None
Alignment: Always lawful or chaotic evil
Advancement: 11-20 HD (Huge); 21-30 HD (Gargantuan)
Level Adjustment: -
Should probably add a subtype in for these, along with the breath weapon and immunity, to make it more draconic than just a half-dragon.