For comparison, a war Elephant is CR 8, with 11d8+55 hp, and some nasty attacks: Slam (+16, 2d6+10), and two Stamps (+11, 2d6+5). And the Elephant can advance up to 22 Hit Dice. Niiiiccceee Elephant...Why'd you think it was too powerful? I whipped one up in pcgen and here is what I got:
M Bulette Beast9 CR 9; Size:H...