(Insert warning here).
DON'T DO THIS
An egg, in the shell. if you've done this, you know what im talking about.
Gremlins
CDs... ooo look at the perty colors
Hamsters
Marshmallows ...seriously they turn to taffee
Aluminium foil
A smaller microwave
Marshmallow Peeps (they inflate to about 3X normal size and burn)
Furbys