I used to work with someone exactly like you describe! We started on the same day and used to go out for smoke breaks and chat about early 80s punk bands like Dead Kennedys and Minor Threat, he had the hairstyle and piercings and his partner was an artist. Both vegans.

But when we started having these departmental meetings that went on for hours with the boss of the company bellowing at us because we only worked our contracted hours, he'd sit there stroking his chin and nodding. He'd regurgitate the bullshit expressions that the boss used, in conversation.

He grassed people up for breaking the daft rules they brought in (e.g. you weren't allowed to ask someone if they wanted to go for a break or for lunch, because it might disturb their work). We had good reason to suspect he helped management draw up their list of ~30 people to make redundant, which was about a third of the workforce.

No foot tapping that I remember, but I was one of the ones who was let go in 2002. It turned out to be exactly the kick up the arse that I needed, but I've been ignoring his requests to add me on LinkedIn for about 10 years.