The only way is to buy one from the Poptropica Store. The ones that appear on Shrink Ray island cannot be costumized.The original Shrink Ray appeared in the ad-game for Despicable Me in June, 2010.
Watch Thinknoodles guide toshrink ray island on youtube
Because the un-shrink ray interacts with the traces of the shrink ray zap causing only previously shunk items to grow.
I am pretty sure that is almost/is impossible.
shove them off
mark
you will call a shipor you will make a boat
Hide behind the round mirror.
MrSilva has the shrink ray he is the one who stole it and shrinks you
A 'shrink' ray is imaginary . . . it does not exist, nor can one be built.
Click the red thing on the left side.
you try to avoid being hit by the shrink ray gun