Facebook Hampster
The Facebook Hamster is the friend who lives in your feed like it's their house. They like your posts, but when you try to talk to them, they're too busy living their own life and ignoring you.
You post a new job. They like it. Then they vanish.
You message them about a party. They reply with a photo of their own meal.
You tag them in a post. They like it. Then they don’t reply for two weeks.