Protector or rescuer alters – these alters can be of any age and were created to save the original person from intolerable situations. These DID alters are often tougher and braver than the original personality.

This definition above comes from here: Understanding Dissociative Identity Disorder Alters - HealthyPlace

They have a list of common alter types with their definitions. I was pleasantly surprised to discover the page - things like the 'common alter types' while I knew of them, I haven't seen anyplace that listed them with definitions. So thanks for asking!