invisible power up

I've been mulling this one over for days with no avail. I'm making a tank game, and part of the game is power ups. One of them, makes the player invisible.

The problem is, I can't think of a way to model an object that would relate to this object. Example, player picks up a shield for shields and a bomb for a nuke, a snowflake to freeze things in spot and a clock to slow down time. But I can't think of a model that would relate to invisibility.

warhawk uses the outline of an eye. crash team racing used two cartoon eyes. i could also imagine using a silhouette of a generic tank (given you're making a tank game). maybe a magnifying glass. or the silhouette of a chameleon.

hope at least one of those is helpful,

julz

Yeah dotted outline of a tank sounds pretty clear

...or a volumetric fog model in the shape of a tank.

I simple, translucent (semi-transparent) tank model (or another object) would get the point across. The object could also fade from fully visible on one side to completely invisible on the other, showing that the object is fading into being invisible.