Shade
Monster Junkie
What kind of CR adjustment do you think we're looking at?
A nagahydra is CR 18, has 18 HD, a similar number of attacks (but employs 1d12 Con damage poison with each bite, which makes a big difference), fast healing 15, and casts as a 15th-level sorcerer.
Compare to our fella, which has 19 HD, much less poison, caster level 12th, fast healing 5, damage reduction 5/good, and the subspecies-specific powers.
Also, a very powerful ability of the nagahydra we might want to borrow here:
"A nagahydra can cast one spell per round per head, but all spells come from the common pool of spells available."
A nagahydra is CR 18, has 18 HD, a similar number of attacks (but employs 1d12 Con damage poison with each bite, which makes a big difference), fast healing 15, and casts as a 15th-level sorcerer.
Compare to our fella, which has 19 HD, much less poison, caster level 12th, fast healing 5, damage reduction 5/good, and the subspecies-specific powers.
Also, a very powerful ability of the nagahydra we might want to borrow here:
"A nagahydra can cast one spell per round per head, but all spells come from the common pool of spells available."