Can I go and sign a co-workers leaving card passive aggressively?
Is there a reason you want to sign the card that way?
Yes, he is annoying and I'm glad he's leaving.
It would be rude to write something passive-aggressive on your coworker's card. If you don't like him, just don't sign the card. Writing something mean is unnecessary.
Maybe, you never know what the future holds.
I know you don't like the person but you can just sign the card and move on, there is no reason to act passive-aggressive. He might end up being your boss one day or doing work at your house. You want to try and be polite to as many people as you can.