The Error End Event element is located in the Event & Gateway drawer of the process editor palette.
The Error End Event can be used to leave the happy path of a process by throwing an error (e.g. if an approval is denied). It can also be used to re-throw previously catched errors.
See the Error Handling concept for sample use cases.
The Name Tab is included in the mask of all process elements and contains the name and a description of the element.
On this tab you can configure the Error Code of the error that will be thrown or the error object that should be re-thrown.