I also posted this on Craft Trends...
Does anyone have any ideas/instructions on how to make a spongebob for a porch? My grandaughter is having a Halloween Spongebob Birthday party and I would like to have his character on the porch by the door. Have lots of craft ideas going on for this party from scarecrows to spongebob. It will be interesting.

When I worked at Walmart (years ago) we had a sponge bob pinata. You could try there or at a party supply.
There is one here, I remember them as being about 20 or so inches tall.

http://www.partycity.com/search.do?query=spongebob