cannibalism sounds like a fun racial skill for the undead, instead of giving it to lizards...
I agree with this suggestion, that seems like it would be a far, far, better fit than with Lizards.
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I also don't really think that a constant HP drain - even if it is only to 80% of your max HP is a very good idea. Isn't this a game which has a lot of places to explore and a lot of people to talk to? Adding a drain effect like that would discourage Undead players from exploring or talking to people.
This is not an action hack + slash where you should be constantly moving forward and attacking, which means that a drain completely counters any possible benefits from starting with +20% HP in the first place! How worthless!
I'll post more feedback later when I think of more things.