Originally, in english courtrooms, wigs would be work to disguise the identity of the judge passing sentench on the unfortunates who were brought in front of him. This knitted woolen one however was more likely work by the Booblehutch, the youngest trainee lawyer within the court at the time.
He could be called at any time by a qualified lawyer by inciting the words:
Booblehutch come hither!
or by making a series of whooping noises.