"An Ontario school board has sent a checklist to parents before Halloween: Does your child's costume 'represent a stereotype,' such as 'terrorist'..."
What is scarier than a terrorist, which is what Halloween is largely about: dressing up in scary costumes. 

"The Viamonde school district's guidelines also address what could be an appropriate costume, which includes animals..."
It could and often is done in a way that mocks other species. Why should that be considered acceptable? They should check their speciesism.