I do a similar thing in which I give the kids a list of idiomatic phrases
such as "I put my foot in my mouth." and have them illustrate it. I have
found, however, that our children have lost this colorful part of our
language. They not only do not use these phrases, they have no clue what
they mean. Consequently, this becomes an integrated lesson when I explain
what idioms are and what they mean.
I love Jude's idea of doing them in clay! Might have to try it.
LInda in NC