we can, but we don't have to. that's kind of boring, predictable, and even stereotypical i figure. we skipped it for Antaeus. though, between the two, i could see Enceladus being more likely to use rocks.
allright, i'm not as opposed to the idea as i seem to be.
Rock Throwing (Ex): The range increment is X feet for Enceladus’s thrown rocks. He uses both hands when throwing a rock.
Rock Catching (Ex): Enceladus can catch Small, Medium, or Large rocks (or projectiles of similar shape). Once per round, when Enceladus would normally be hit by a rock he can make a Reflex save to catch it as a free action. The DC is 15 for a Small rock, 20 for a Medium one, and 25 for a Large one. (If the projectile provides a magical bonus on attack rolls, the DC increases by that amount.) Enceladus must be ready for and aware of the attack in order to make a rock catching attempt.
"A giant of at least Large size can hurl rocks weighing 40 to 50 pounds each (Small objects) up to five range increments. The size of the range increment varies with the giant’s variety. A Huge giant can hurl rocks of 60 to 80 pounds (Medium objects)."
Using this progression, a Colossal Giant should be able to hurl rocks of up to Huge size, weighing I don't know, 200 to 400 pounds?
Here's how the range increments break down by type and size:
Fensir (Large): 120 ft.
Rakka (Huge): 120 ft.
Bog (Large): 120
Hill (Large): 120
Lesser Cyclops (Large): 120
Fog (Huge): 140
Stone (Huge): 180
Frost (Large): 120
Fire (Large): 120
Cloud (H): 140
Greater Cyclops (H): 140
Forest (H): 120
Firbolg (H): 130
Death (H): 120
Shadow (H): 120
Geriviar (H): 160
Ocean (H): 120
Mountain (C): No range given.
The standard appears to be 120 for Large and 140 for Huge. Although that's not much to go on to construct a formula, if we just assume 20 feet more for each size category, we'd have: