I thought you would need to go deeper to get enough resources to build such a set
It took some work. Fortunately, proper use of potions of ambidexterity meant I could do it with surprisingly few scrolls of the big stick.
It's still an intermediate stage, though. I've worked out what I think is the perfect set of weapons for an Echidna to carry; the downside is, from where I am now, I need to pick up another 459 scrolls of the big stick and probably a hundred or so potions of ambidexterity, on top of that, so it'll take a while. (I've got all the scrolls of reforging that I'll need, fortunately).
As for your idea of Cerberi, they could be fun, but they also would be a real trouble for the Echidna race. After each Echidna move, they would get 4 moves (approach, approach, hit, run). Echidna seems to be the easiest race now (most reports seem to use them), so it might be a good idea to nerf it, but being hit after each move (unless using two potions of speed) seems to be too evil...
Hmmm. True. I was thinking more thematically than game-balancely.
Though a potion of mushroom spores could probably ward it off for a bit. Actually, that leads to another thought; thrown potions. It may be reasonable to throw a potion, in order to affect a hydra from a distance with a ranged attack. Of course, in general, one wouldn't want to throw any of the current potions; one might want to throw a potion of slowness, or a potion of stunning, even a potion of transmutation to change one hydra type to another (oh no, a werehydra when I only have ash weapons!) Or throw a potion of mushroom spores, to have a batch of mushrooms spring up one square short of the nearest obstacle or hydra. Or maybe throw a potion of speed at the nearest zombie hydra...
This may also lead to new ways to deal with giants and monkeys; it makes sense that they wouldn't be able to dodge a cloud of potion that sprays everywhere when the bottle shatters.