I call them Ghouls and Ghosts.
Ghosts are players that join your corporation and then you never hear another word from them. They don't participate on Discord, or in chat, they just sort of linger in the margins until one day they vanish without a trace. And while they may often have legitimate real life reasons for this, those that do are not actually Ghosts. Those are what I call Bad-Timers. It was just a bad time for them to join. Ghosts don't have a legitimate reason for vanishing. How do I know this you ask?
I know this because I hear about it later. Ghosts will pop up on recruitment threads, or on Reddit, or in a Discord discussion (often randomly and without much reason) to debunk anything positive someone happens to say about your group. They know, you see, because they used to be in your group. And your group ain't what it used to be. And then they will rattle off all the reasons for this, all from their own personal experiences. I had this happen recently on Reddit. Dude just trashed Stay Frosty. So I got him to admit to his player name and looked him up - yeah he used to be in our corporation. He flew in Null Sec mostly, which as everyone knows, is NOT where Stay Frosty operates. No one remembered him. Why? Because he was a Ghost. Zero results when I did a Discord search.
Ghouls share some common elements with Ghosts, but they join for entirely different reasons. Ghouls join your group for an extremely specific reason. An extremely negative or personal reason, usually to prove a point of some kind. If the reason is theft they become Corp Thieves and that is a different category. Mostly Ghouls want to cause trouble, or start a war, or steal a specific asset, or get someone in trouble for a grudge they've been holding onto. We've actually had all of those happen in SF/ABA at one time or another. And once they've achieved this goal they usually leave without a trace. But they never really leave, they will continue to hang out in your public channels.
There are other kinds of members. And many times a person can be more than one kind. Spotlights are new recruits that, for some unknown reason, believe everything is about them. That any blog posts written in these pages while they were members was about them for example.
What other kinds of members have you seen in your own Corp/Alliance over the years?