I'm currently listening to Fear to Tread, and apparently, some do indeed have fangs; though far fewer legionaries seem to sport them than in the space puppy brigade. I think it's a side effect of the red thirst, or a predisposition to the thirst.
The
is described as being fanged. It is somewhat unclear if they simply appeared fang-y because of his menacing snarl, or actual pointy teeth business.
(sorry to bump an older thread. don't be angreh!)