I couldn't think of any better name, sorry. -_-
I was thinking about something, sort of like the Folly Fun Card, typing in a command and then having something like an emitter or color for your player, that would basically set your player apart from a normal player. For example:
/flameplayer - Your entire player bursts into flames, not hurting him, just setting the flame emitter on him.
/ghostplayer - Your whole body is a transparent white/gray, and you have a bit of fog around you.
/bloodyplayer - You leave a trail of blood behind you (disappearing after a little while of course) and are sort of dripping blood.
/brightplayer - a bright light coming from your player's face, or from his entire body, pretty much blinding whoever looks at him.
/blurryplayer - your player lokos sort of blurry, and leaves behind a trail of himself... sorta... like when he walks, you see what you would see if you took a picture of something that was moving. (Couldn't think of a better way to describe it.)
/shakyplayer - Your player looks like he's vibrating, like he's rumbling around or something.
Get the basic idea? o_o