Pencils have cores based on graphite or charcoal.

Pencil crayons have cores based on wax or oil, with pigments added. This is basically the composition of crayons or pastels. Then it's wrapped in wood like a pencil. Thus ... "pencil crayon".

There are also various different ways to pronounce “crayon”; is that also true in Canada? For example I pronounce it with one syllable: “cran”, just like the beginning of “cranberry”. I get the feeling that’s not the majority pronunciation but it’s not exactly rare either (at least where I grew up).