Let's try 'em at 16 and 32 and see how they look.
That sounds like a cue, so how's this for a start:
Shouldn't the regular Gargantua have Crush 8d12+30
or 8d12+20? Giving it 1.25 its Strength bonus doesn't seem right. I've opted for 1.5 Str for the examples below.
Gargantua, Humanoid, Infant
Huge Giant
Hit Dice: 16d8+128 (200 hp)
Initiative: +1
Speed: 60 ft. (12 squares)
Armor Class: 30 (-2 size, +1 Dex, +21 natural), touch 9, flat-footed 29
Base Attack/Grapple: +12/+32
Attack: Slam +49 melee (2d10+12/19-20) or rock +30 ranged (2d6+12)
Full Attack: 2 slams +49 melee (2d10+12/19-20) or rock +30 ranged (2d6+12)
Space/Reach: 15 ft./15 ft.
Special Attacks: Crush 4d12+18, fling, rock throwing, stomp, trample 3d10+12
Special Qualities: Damage reduction 10/epic, empathic sense, fast healing 20, low-light vision, rock catching
Saves: Fort +18, Ref +8, Will +9
Abilities: Str 35, Dex 13, Con 27, Int 5, Wis 14, Cha 16
Skills: 19
Feats: Cleave, Improved Bull Rush, Improved Critical (slam), Iron Will, Lightning Reflexes, Power Attack
Environment: Warm and temperate mountains
Organization: Solitary, mated pair or family (2 adults and 1-2 children)
Challenge Rating: 9
Treasure: None
Alignment: Always chaotic neutral
Advancement: 17-31 HD (Huge); 32-49 HD (Gargantuan), 50+ HD (Colossal)
Level Adjustment: —
Gargantua, Humanoid, Juvenile
Gargantuan Giant
Hit Dice: 32d8+320 (464 hp)
Initiative: +1
Speed: 60 ft. (12 squares)
Armor Class: 36 (-4 size, +1 Dex, +29 natural), touch 7, flat-footed 35
Base Attack/Grapple: +24/+52
Attack: Slam +36 melee (3d10+16/19-20) or rock +21 ranged (3d6+16)
Full Attack: 2 slams +36 melee (3d10+16/19-20) or rock +21 ranged (3d6+16)
Space/Reach: 20 ft./20 ft.
Special Attacks: Crush 6d12+24, fling, rock throwing, stomp, trample 4d10+16
Special Qualities: Damage reduction 10/epic, empathic sense, fast healing 20, low-light vision, rock catching
Saves: Fort +28, Ref +17, Will +18
Abilities: Str 43, Dex 13, Con 31, Int 5, Wis 14, Cha 18
Skills: 35
Feats: Awesome Blow, Cleave, Dire Charge, Epic Reflexes, Epic Will, Improved Bull Rush, Improved Critical (slam), Iron Will, Lightning Reflexes, Power Attack, Track
Environment: Warm and temperate mountains
Organization: Solitary, mated pair or family (2 adults and 1-2 children)
Challenge Rating: 15
Treasure: None
Alignment: Always chaotic neutral
Advancement: 32-49 HD (Gargantuan), 50+ HD (Colossal)
Level Adjustment: —
