The
Lycanthrope template is quite specific. There are two base creatures involved, one's type is either humanoid or a giant while the other's is animal and is further specified as being a predator, scavenger, or omnivore, so probably no animals that only eat things that are both alive and inanimate... I suspect that the intended distinction is that it is only animals that eat other animals, but it doesn't say that so...
If you want a homebrew something... Well, you could just play as a hydra, though you would want the intelligence bumped above animal level...
Alternatively you could be a half-hydra, simple enough to do if you have someone who is very bored and has more skill with polymorph than ethics...
Lets think, what do hydras have...
huge, magical beast, slow, natural AC, many heads, fast healing, scent, darkvision, low-light
con, str, dex, cha, wis, int
Right, base of two heads, +1 LA for each additional head, maximum of six heads.
Fast healing 1 +1 for each additional head.
Secondary bite attack, probably 1d4 at medium size, adjust for different sizes...
+4con, +2str, -4int
+2 to listen, spot, swim, and survival.
+2 natural AC, +1 per additional head.
two monster hit dice.
Make them pay double base price for armour to get it fitted to a strange body form.
Well this is a start, I am not sure about type changes, probably give it a base LA of +1 so a two-headed half-hydra/half human would have to start at level three at a minimum.
Human, 2 hit dice, fast healing 1
19 str(13), 18 con(6), 13 dex(5), 13 int(
, 8wis/cha(0)
humanoid: 2d8+8=8+8+4.5=20
BAB=1 Bref=3 Bfort/will=0 skills=3*5=15(give them the commoner skill selection for these hit die.((I suggest letting people offset their four times skill points until their first class...)))
So...
20 hit points with fast heal 1
+6(2d4+6 master-work spiked chain) +0+0(1d4+2 bite)
AC 21 (10+8FP+2nat+1dex)
Saves= F4 R4 W-1
level = 3
...
Could work... maybe add +1 LA for pyro or cryo, give them 1d6 damage per head on their breath weapon and the appropriate subtype...