Death From Above
Golem/Catapult: Earthbending DC 39
A growing shadow appeared around the witless firebender. "Huh? What?" *THUMP*
Note: Reflex for half. If you fail, Fort to avoid being knocked prone. The golem gets a standard action. Range 10 ft. Full round action to use.
Edit: Upon a re-read, you may be able to use this seed anywhere within your bending range.
The Fort save and reflex save increase by 5 for every size larger than medium the Golem is.
Size
Medium: 2d6
Large golem(+5 DC): 8d6
Huge:66d6
Gargantuan(+10 DC): 500d6
Colossal(+15 DC): more than 500d6.
Damage increment per +4 DC (+5 ft range)
Medium: 2d6
Large: 8d6
Huge: 66d6
Gargantuan: 500d6
Colossal: more than 500d6.
These are according to critter weights in the SRD, assuming you launch the golem 10 ft in any direction. I'm going to assume for brevity that you don't want the golem to land on you. Edit: Also, that means that you have to add +4 for a Gargantuan critter, and +12 for a colossal golem, just so it doesn't land on you too. Sorry about lack of tables. I don't know quite how they work.