I don’t want to start associating them with the landwyrms; this is a separate species. Elder wrym might just work. Maybe even great elder wyrm.
Did some work on the stat block:
Wyrm, Great
Gargantuan Dragon (Air?)
Hit Dice: 32d12+256 (467 hp)
Initiative: +0
Speed: 40 ft (8 squares)
Armor Class: X (-4 size, +X natural), touch X, flat-footed X
Base Attack/Grapple: +13/+40
Attack: Bite +24 melee (4d10+15)
Full Attack: Bite +24 melee (4d10+15) and 2 claws +19 melee (4d6+7)
Space/Reach: 20 ft/15 ft
Special Attacks: Breath weapon, fast healing X, frightful presence
Special Qualities: Blindsense 60? ft, darkvision 60 ft., immunities (disease, paralysis, sleep), low-light vision, see invisibility?, spell resistance X
Saves: Fort +26, Ref +18, Will +25
Abilities: Str 39, Dex 10, Con 27, Int 20, Wis 20, Cha 24
Skills: 385 (Knowledges)
Feats: 5
Environment: X
Organization: Solitary
Challenge Rating: X
Treasure: X
Alignment: Usually neutral evil
Advancement: 14-26 HD (Gargantuan); 27-39 HD (Colossal)
Level Adjustment: ---
Speak Draconic and “any”
COMBAT
Originally found in Dragon Magazine #94 (“Creature Catalog II,” February 1986, Roger Moore).