It comes from the expression "se crêper le chignon", which means to fight, to argue. It’s usually used for women.

Here, it’s a vague name calling, probably to say Collignon is annoying or mean.

Also, the correct way to write it to be crêpe-chignon (with a hyphen). Kind of like casse-pieds, which is an adjective or a noun for "quelqu’un qui casse les pieds".