An Invisibob is a special avatar glitch from Gaia Online. This avatar glitch was only possible on April Fools' Day of 2004.

Since the YGS, or "You got Served" boxes, exploded in your avatar's face, it looked like there was soot on it.

The Administrators had planned for it to go away after 24 hours, but it didn't - they'd stay until you saved changes to your avatar. Thus, this led to two types of rare avatars: the Sootfaces and Invisibobs.

An Invisibob was created by deleting your avatar data, then clicking on a YGS box. The resulting explosion glitched the avatar system and forced your avatar to go to the default base - a Soot-face and a pair of floating boxers.

...See one on Gaia Online, by doing a search in the memberlist for "Sevi Rais.".
"Sevi Rais", "Weeping Willow", and "Teh Ghost of Bap" are all Invisibobs.
or
I wish I were an Invisibob. Instead I'm an Invisibob Wannabe.
by Kenjoki Ikari January 26, 2005
Get the Invisibob mug.
A wannabe Invisibob is basically someone who can't be an Invisibob, but wants to be.
Therefore, they wear normal clothes, yet hide their face so as to remember our radioactive, floating, boxer-shorted, invisible friends.

...See Gaia Online.
"Kenjoki, you are SUCH a Wannabe Invisibob!"
or
"You are an Invisibob Wannabe. Take off those masks."
by Kenjoki Ikari January 26, 2005
Get the Wannabe Invisibob mug.
Exact same as a Wannabe Invisibob.

Just word order switched around.
Invisibob Wannabes are just like Wannabe Invisibobs. Mkay?
by Kenjoki Ikari February 3, 2005
Get the Invisibob Wannabe mug.