I worked with a guy who was absolutely obsessed about this small, regional marketing agency I used to work with. He wasn't a "partner" or had any stake in the company, just a regular, salaried employee.

He volunatrily worked nights and weekends, for free. Any outside event associated with work, he would always show up to, like charity walks or happy hours.

If someone put their notice in, he would try to make comments about it, in front of other people. He would stop talking to people who left for other jobs, even if he was friends with them. He would give you attitude if you left work at normal working hours.

He was constantly bringing food in and not just donuts he bought in the way in, real gourmet food spent alot of time and money on. He redecorated our entire work area over a weekend by going to Ikea and buying new desks and paint and lights (company funded).

He would plan holiday lunch "events" like tracing your hand and decorating thenm like turkeys for Thanksgiving and hanging them on the wall (grown men were doing this) or pumpkin carving for Halloween.

He would also plan meetings with other departments, going over our boss's head to do it. He once said the only way he would ever leave the company is if "the place burned down".