Machete - Thanks for the link.
It certainly looks like a painted frogfish.
Most of the stuff I found also points to this.
I did however, find a pic of a Warty that looks like it too.
So I guess I'll have to wait until he's a bit bigger to see for sure.
Tony - I've moved him out of the QT tank so he wont be hassled by the Butterfly. I've put him in a 10g for now. Hopefully I can find a more permanent home for him to grow.
Myka - I'm crossing my fingers that he morphs into something a little less drab than brown. Maybe if I can give him a home with lots of bright pink coralline covered rocks & colourful sponges or corals he'll morph into those colours instead.
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