Big Giant Snake

During season 2, it's made clear that the city council is aware of the local supernatual on-goings, but they do all they can to keep it as secret as possible. The police and even the HS principal are involved.

On the High School vampire attack:
Police Chief: I'll need to say something to the media.
Snyder: So.
Police Chief: So, usual story? Gang-related, PCP?
Snyder: What did you have in mind? The truth?
Police Chief: Right. Gang-related. PCP.
    - School Hard

On the snake infested cafeteria:
Police Chief: Schoolboy prank?
Snyder: Never sell.
Police Chief: Backed-up sewer lines?
Snyder: Better. I can probably make that one fly. But this is getting out of hand. People will talk.
Police Chief: You'll take care of it.
Snyder: I'm doing everything I can. But you people have to realise - (a group of people walk past near them) Backed-up sewer lines, this happened in San Diego just last week - that we are on a Hellmouth. Sooner or later, people are going to figure that out.
Police Chief: The city council was told you could handle this job. If you can't... perhaps you'd like to take that up with the mayor.
Snyder: I'll handle it. I will.
    - In Only Have Eyes For You

On Buffy:
Snyder: In case you didn't notice, the police in Sunnydale are deeply stupid. It doesn't matter anyway. Whatever they find, you've proved to be much of a liability for this school... These are moments you want to savor. You wish time would stop so you can live them over and over again. You're expelled.
Buffy: You never got a single date when you were in High School, did you?
Snyder: Your point being? - Buffy leaves and Snyder grabs his phone - It's Snyder. Tell the Mayor I have good news.
    - Becoming.

The Mayor is aware of the mystical activity current in the town, and has been watching Buffy for a while. It also turns out to not be as squeaky clean as the townies think. He is ready to kill, and has certainly killed before, to get what he wants.

Mayor: Well, as I understand it, you're not a man... exactly. Mr. Trick, I've been the Mayor for quite some time. I like things to run smoothly. This is a very important year for me.
Trick: Election Year.
Mayor: Something like that.
Trick: Is this the part where you tell me that I don't fit in your quiet little neighborhood, you can just skip it, cause see, that all got old long before I became a vampire. Do you know what I'm saying?
Mayor: Do you have children? Children are the heart of a community. They need to be looked after. Controlled. The more rebellious element needs to be dealt with. The children are our future. We need them. I need them.
Trick: If this rebellious element means who I think it does, then that problem may be taken care of this very night.
Mayor: So I've heard. That's a very enterprising idea you have. Slayerfest. I love that name, by the way. You see, that's the kind of initiative I need on my team.
    - Homecoming

Mayor: I've made certain deeds to get where I am today. This demon requires its tribute. (the tribute happens to be several newborn babies)
    - Band Candy

To collect the tribute, the mayor hires Ethan Rayne. He makes some poisoned chocolate which turns all the adults into retarded teens to distract them for the kidnapping. Once again Snyder is involved, since the chocolate is sold by SHS students.

The mayor takes over all evil in town. Everything bad that happens is pretty much related to him. When someone gets in the way, even if that someone technically is evil, he has it taken care of.

Why don't you take care of that Spike problem? A committee, like you said.
    - Lovers Walk.

Indeed a committee is sent to greet Spike, and also dust him while they're at it. The committee is composed of vampires, which proves that the Mayor has leagued up with them.

So he's the Mayor, but Richard Wilkins III the man is pretty peculiar... Here are some quips.

Moist towelette?
    - welcoming Mr. Trick, Homecoming.

Oh, look at that! Every time, cuts to the left. See, and it's not the carpet, it's me.
    - practicing golf in his office, Lovers Walk.

Mayor: Loose canon. Rock the boat. Is that a mixed metaphor?
Allan: Uh...
Mayor: Boats do have canon. And a loose one would cause it too rock. Oh honestly. I don't know where my mind goes these days.

    - Lovers Walk.

I just love the Family Circus
    - Bad Girls.

Oh! Eww! He's always on the furniture. Unsanitary.
    - about the dog in Family Circus, Bad Girls.

It's supposed to cheer me up. Usually using the shredder gives me a lift. It's fun
    - watching the shredder tear up some paper, Consequences.

Angel: Mmmm. can't be killed, but you don't like germs?
Mayor: Uck, eew, awful things. Unsanitary.

    - Enemies.

to be continued