I kinda like random abilities, regardless of size. Spot checking a few of the names, it looks like serpent tails for legs were a repeated theme, and "born with armor and weapon" was another.
Looking at stats of the two we've got...
Antaeus (L): Str 25, Dex 10, Con 19, Int 8, Wis 11, Cha 12
Enceladus (C): Str 53, Dex 10, Con 45, Int 7, Wis 13, Cha 14
...and comparing to other giants, perhaps base ability scores of...
Large: Str 25, Dex 10, Con 20, Int 8, Wis 11, Cha 12
Huge: Str 35, Dex 10, Con 24, Int 8, Wis 11, Cha 12
Gargantuan: Str 43, Dex 10, Con 28, Int 11, Wis 13, Cha 12
Colossal: Str 51, Dex 10, Con 32, Int 8, Wis 11, Cha 12
...and allow a random boost to one or more stats?