This game is more of a sharing game rather than an interactive game, however there should be some interactions. The idea is you comment on the previous poster's nickname and/or reason [this can be a tangent to whatever they said, it doesn't have to be just something like oh that's a nice name, indeed the more interesting the comment the more fun the game] then you share a nickname and the reason behind it. It can be any nickname - your nickname, a nickname you give someone/something, whatever.

It will hopefully be a nice way to get to know each other better.

For example:
Poster One: I call Maine Coon cats moon cats because I always end up smashing the main coon together.
Poster Two: That's pretty cool, it makes me think of Luna from Sailor Moon. I call my brother Sparky because he's always destroying computers.

To start it off:
One of my many nicknames is Chewtoy. I got it when I worked at a shelter that did adoptions at a Petsmart. They had a large pen where they'd put several of the better behaved dogs together, so people could see them playing and get a better idea of their personality. One volunteer had to stay in the pen at all times, in part to break up any fights and in part to catch dogs to bring them out so potential adopts could get to know the dogs. I was typically the pen-girl and I was constantly fending dogs off of my clothing, shoes and so forth.

Chewtoy, huh? I could swear there was a juicier story behind that succulent nickname LOL

I used to call my little sister 'The Caotonic Menace' until the age of ten. On one especially chilly day my little sister refused to wear an overcoat. I argued that it could snow, so she should wear one. It didn't snow, but when I came home everything were covered in cocoa powder. My sister jumped up and down, yelling 'Snow' while pointing everywhere. She was six and had never seen snow, so she didn't know it wasn't supposed to be brown. The smell never quite left my wardrobe. Yeah, she spread it everywhere...and I do mean everywhere.