[RichardHorrocks]

Hi folks - new poster here.

I'm trying to identify an action figure that I found in a big box of secondhand Lego in the late 1980s (in the UK). It's continued to sit in that box until now. (I'm having a clear-out.)

It's transparent blue/white, and transforms into some sort of rudimentary diamond shape.

Any help in working out what it is would be much appreciated.