Think the wackiest so far has to be the 'Temple of Doom'! Primary school teachers have a lot to answer for IMHO. I remember when DD, aged about 8 or 9, came home the day before Open Evening, saying she had been chosen to help and the teacher had said they had to "come dressed as the rainforest". After some research I produced her costume: forest floor (shoes), understory (leaves and flowers round her ankles), canopy layer (green skirt) and emergent layer (a crown of greenery). When I went in the next night it transpired she was expecting the sort of clothes worn by a rainforest inhabitant. Glad I didn't insist on the parrot in her knickers.