I've worked with some nutty people, but not too many creepy ones. But there were 2.
1. A guy I worked with about 10-15 years ago. Most of the staff were twentysomethings, I was a thirtysomething, he was probably closer in age (or even older) than me. He just creeped all the women out--he was always staring at us. He also wanted you to have conversations with him on the most inane things. But the weirdest thing was the way he would follow the female who was training him. He would wait outside the ladies room so he could ask her a question. And he wasn't able to handle the job. So one day, as she was going over his work with him and showing him his mistakes, he got up, said "I can't take this anymore" and stalked out of the office, never to return. Weird.
2. A woman we worked with about 2 years ago. She was just the most unpleasant person I have ever met in my life. Nasty to everyone. Everyone else made mistakes, not her. She was keeping track of anyone's hours, going thru people's desks when they weren't there, just really mean. When they replaced our computers, some people had asked if we could take the old ones, we were told we couldn't have them. She saw them in dumpsters and called her boyfriend to come & take them. (before he could get into NYC, they had been carted away) The final thing was when she cheated on her OT. We used to be allowed to do some work at home. She claimed lots of hours, but didn't do the work. Of course, she thought she was getting away with all of this--but what she didn't know was the boss had been watching her carefully. One day last June, she was told to go to HR--and she was fired! Everyone breathed a sigh of relief.