i have used Metalslug as my nick for gaming since the 90's. I used to play the Neo Geo side scrolling shoot em up arcade game Metalslug all the time at my local Pizzeria's and bowling alley.
i use slug on most non gaming sites and forums, like here and CALGUNS.com
My avatar is RTT CQB guy from youtube, he is a highspeed Low drag operator Slaying bodies Good 2 Go.