So Ground and Ghost would be problematic, though the more common Ghosts don't have much to fear from Toxistalling anywhales, no? (Gengar, Sableye, Dusclops... I suppose the latter might be a bit worried, but could also likely outstall)
And it's always goo to have a weakness somewhere, right? Arbok would certainly be death to Fairies though
I'm thinking: Toxic/Poison Fang(Handy if you want to run a boosting move in the last slot, maybe Coil? To help do some actual damage), Wrap/boosting move, Rest, Poison attack/Iron Tail/boosting move