A tactic I might employ if I were in the same situation.... As others have suggested, do exactly only as much as you are required to by your job description. Take care of the kids, but nothing extra. But here's the thing I would add:
Over-document everything. If the super so much as says "hello" to you in the hall, follow it up with an email to him and say something like "Just so we're on the same page...in the hall today, you said 'hello'. I just wanted to make sure that I understood that correctly, as merely a greeting with no other intentions behind it. Is that correct?"
Do that for everything. Verbal conversations, meetings, phone calls, etc.
#1, this puts him/her on notice that you are documenting the heck out of everything.
#2, it annoys the crap out of him/her, while doing absolutely nothing wrong.
#3, it might push him/her far enough to do something extremely stupid and unrecoverable.
Good luck and I hope your suit makes it so this person never works in education again.