I recall 3.0
e size categories for weapons,
to be effectively un-capped. By now, where
I got that idea, has drifted off into my kitty avatar's past life(s).
There's just a little bit too much Collosal++ fire out there
for the constant bubbling up, to be nothing.
Conceptually, it should work no problems.
I did find this reference at giantitp :
Runestar - Elder evils has the leviathan.
1 version is 50-ft space, with 20ft reach.
The 2nd advanced version is 60-ft space, but still 20ft reach.
Natural weapon damage and physical stats seem to have been improved arbitrarily (eg: its slam damage improves from 4d6 to 5d6, but tail slap remains unchanged).
Str and con increased by +4, NA by +10. Again, no apparent link. http://www.giantitp.com/forums/showsinglepost.php?p=9982956&postcount=8
I can't confirm. No access to Elder Evils.
It doesn't look to me like an actual Size Category,
it does represent something rather close to that.