"Well gosh!"
Mayor Richard Wilkins seems a pleasent chap who cares very deeply for his town. Very involved in community life, the Mayor shows Boy Scouts around his City Hall as well as going to PTA meetings. A very pleasant chap, there doesn't seem to be anything suspicious about him.
But how wrong can you be? The venerable Mayor is really over a hundred years old (although he looks no more than fifty). He actually founded Sunnydale all those years ago, knowing full well that it was on the Hellmouth and turned it into the demon-magnet it is today. he has his fingers in many pies too, with power of Snyder and the Chief of Police, Wilkins runs Sunnydale the way he wants it run.
A cabinet in his office reveals his dark nature, full of skulls and various other black magic implements as well as bottles of scotch and other items he can use for bribery.
There is more to his grand ambition than just making Sunnydale safe for the creatures of the night. For many, many years he has been preparing himself for the Ascension, the time when he can cast off his mortal shell and become the most powerful immortal demon in the world. And the day he chose to do this? Graduation Day 1999.
Wilkins doesn't work on his own though. His right hand man was Alan, the Deputy Mayor, until Faith killed him and then Mr. Trick, his link to the darker side of town, until Faith killed him too. So the Mayor enlisted the help of the second strongest person in Sunnydale, rogue Slayer Faith. But theirs was more than a working relationship, Faith was the daughter the Mayor could never have, and treated her as such, showering her with lavish gifts (the knife, the apartment) and getting her to dress in pretty clothes while getting her to do the dirty work, (spy on Buffy, get the books of Ascension). When Faith was put into a coma by Buffy, the mayor vowed painful revenge on Buffy and even tried to kill her while she was unconscious, luckily Angel stopped him.
When the time of Ascension came, the Mayor vowed to kill Buffy and all her friends, but it was his fatherly love of the rogue Slayer that proved his undoing. When Buffy confronted him with Faith's knife covered in Faith's blood, he went crazy, forgetting his own plans of destruction to kill the Slayer who hurt his 'daughter'. Unfortunately his blind anger and chasing of Buffy led him to an explosive end in the Library which was packed for of explosives.
Mayor meat anyone?
The Mayor might be gone, but he isn't forgotten. A return trip to Sunnydale High had Xander stepping in some anonymus part of the Mayor while Faith still dreams about the person she saw as her surrogate father.