Okay, how the hell do I kill it? (other than the obvious chop chop chop...)
It hits me before I get near it with some sorta nasty spell and it's game over!
My lizard dude has 95% protection from poison and still dies from it WTF!
any ideas, any?

The best method is a 5th level fire spell - Burning Haze. Lob one in from a distance and then get out of rrange and wait for ti to do its job. You may need a few of them depending on how many Mantraps/Lilies there are.

Otherwise, other ranged fire spells will work. The trick is to stay back and wittle them down. As a last resort - run!