I was looking through the construct bonus HPs in the Epic Bestiary when I noticed a discrepancy. The standard contruct bonus HP is as follows:
Fine = +0 hp
Diminutive = +0 hp
Tiny = +0 hp
Small = +10 hp
Medium = +20 hp
Large = +30 hp
Huge = +40 hp
Gargantuan = +60 hp
Colossal = +80 hp
Now if we extrapolate these values using staggered doubling as you said, we get the following:
Titanic = +120 hp
Macro-Fine = +160 hp
Macro-Diminutive = +240 hp
Macro-Tiny = +320 hp
Macro-Small = +480 hp
Macro-Medium = +640 hp
Macro-Large = +960 hp
Macro-Huge = +1,280 hp
Macro-Gargantuan = +1,920 hp
Macro-Colossal = +2,560 hp
Macro-Titanic = +3,840 hp
Mega-Fine = +5,120 hp
Mega-Diminutive = +7,680 hp
Mega-Tiny = +10,240 hp
Mega-Small = +15,360 hp
Mega-Medium = +20,480 hp
Mega-Large = +30,720 hp
Mega-Huge = +40,960 hp
Mega-Gargantuan = +61,440 hp
Mega-Colossal = +81,920 hp
Mega-Titanic = +122,880 hp
Giga-Fine = +163,840 hp
Giga-Diminutive = +245,760 hp
Giga-Tiny = +327,680 hp
Giga-Small = +491,520 hp
Giga-Medium = +655,360 hp
Giga-Large = +983,040 hp
Giga-Huge = +1,310,720 hp
Giga-Gargantuan = +1,966,080 hp
Giga-Colossal = +2,621,440 hp
Giga-Titanic = +3,932,160 hp
Tera-Fine = +5,242,880 hp
Tera-Diminutive = +7,864,320 hp
According to the rules for Virtual Size Categories presented in the Epic Bestiary, constructs with VSCs receive bonus hp as if they were constructs of the adjusted size (so a Huge construct with 2 VSCs would count as a Colossal construct for the purpose of bonus hp, and would thus receive +80 hp instead of +40 hp). However, some of the golems receive in the bestiary receive too little or too much construct bonus hp for their adjusted size:
Orichalcum Guardian (Medium size, +15 VSCs from Orichalcum, effectively Macro-Titanic size) = +3,840 hp (originally +5,120 hp)
Orichalcum Golem (Large size, +15 VSCs from Orichalcum, effectively Mega-Fine size) = +5,120 hp (originally +7,680 hp)
Orichalcum Sentinel (Huge size, +15 VSCs from Orichalcum, effectively Mega-Diminutive size) = +7,680 hp (originally +10,240 hp)
Orichalcum Gargant (Gargantuan size, +15 VSCs from Orichalcum, effectively Mega-Tiny size) = +10,240 hp (originally +15,360 hp)
Orichalcum Colossus (Colossal size, +15 VSCs from Orichalcum, effectively Mega-Small size) = +15,360 hp (originally +20,480 hp)
Orichalcum Leviathan (Titanic size, +15 VSCs from Orichalcum, effectively Mega-Medium size) = +20,480 hp (originally +30,720 hp)
Neutronium Golem (Large size, +32 VSCs from Neutronium, effectively Giga-Gargantuan size) = +1,966,080 hp (originally +1,310,720 hp)
Another thing I noticed was that an animated moon/planet or a golem with the shape, size, and density of a moon/planet simply has so much more HP than just a regular moon/planet. Let's take the earth for example. It has a mass of approximately 6.58 zettatons (according to my extrapolated size category weights, that should fall under the approximate mass of a Mega-Titanic creature, 1-8 zettatons), and with the rule that inanimate objects have hp equivalent to the bonus hp that a construct of their weight would have received, the earth has approximately 122,880 hp. However, if the earth were to be turned into an animated object, it receives HD since it's now a construct, and using the rule that spherical creatures have HD equivalent to the creature's diameter in feet (the earth has a mean diameter of about 7,919.744939553 miles), the earth is now a 41,816,253 HD Mega-Colossal animated object. That obviously has a lot more hp than when it was as just an inanimate planet, and that's not even including its construct bonus hp.
Let's try a sentient earth from a different approach by instead creating a golem in its likeness. According to the bestiary, a golem's HD is equivalent to [9 + 1/2 Material Strength Modifier], adjusted by the size of the golem. Since a Huge golem is x2, a Gargantuan golem is x4, a Colossal golem is x8, and a Titanic golem is x16, we can extrapolate from this doubling progression the following table:
Macro-Fine = x32
Macro-Diminutive = x64
Macro-Tiny = x128
Macro-Small = x256
Macro-Medium = x512
Macro-Large = x1,024
Macro-Huge = x2,048
Macro-Gargantuan = x4,096
Macro-Colossal = x8,192
Macro-Titanic = x16,384
Mega-Fine = x32,768
Mega-Diminutive = x65,536
Mega-Tiny = x131,072
Mega-Small = x262,144
Mega-Medium = x524,288
Mega-Large = x1,048,576
Mega-Huge = x2,097,152
Mega-Gargantuan = x4,194,304
Mega-Colossal = x8,388,608
A Mega-Colossal creature with humanoid proportions would have a height of 12,288-24,576 miles, and we half that for the diameter of a spherical creature (bringing it down to 6,144-12,288 miles), and since the earth has a mean diameter of 7,919.744939553 miles, the earth is a Mega-Colossal creature. The earth has a density of 5.513 grams per cubic centimeter which means it would weigh approximately 4.6 times heavier than a creature made of flesh and bone (1.2 grams per cubic centimeter), giving "earth material" (consider things fashioned from it having a crust, mantle, and core) a material strength modifier of +23. Therefore, a Mega-Colossal golem made of "earth material" would have HD equivalent to [(9 + 11) x 8,388,608]. Thus, a Mega-Colossal spherical golem with the exact composition and density of the earth would have 167,772,160 HD.
So why exactly does a creature with the exact dimensions and density of the earth have millions more hp than just the earth? And why does a golem with the composition and size of the earth also have millions more hp than a non-golem creature with the size and material of the earth?
