An abridger is someone who makes or helps make an abridged series. Bareing in mind that this comes as a second-nature term, and many abridgers may not even like the term "abridger", opposed to "parodier".
There are a few things that you need in order to be an abridger.
A Name Edit
In order to protect yourself from relentless fans and critics, you need to make a user name. It generally helps to make it unique and not a rip off of another abridger's name. Using a slightly modified version of another abridger's name makes it look like your series is so poorly done that you have to leech of someone else for viewers. A name is not fully required, though, as many abridgers publicly release their names. And abundance of numbers and symbols in one's name can also reprive one of having a memorable name.
A First Episode Edit
To be an abridger, one must release at least one episode of material. Trailers and previews do often count, to most people, but there are those who feel a first episode is required.
There are three primary roles an abridger can fill or they could fill all of them. They are: Voice Acting, Editing, and Scripting. One needs to either script or voice act to be considered an abridger, however. If they only edit, a person is outsourced assistance. While still deserving a credit, this isn't entirely the same.
Voice Acting Edit
Voice Acting is the most public of the three since the voice is heard by the audiance. Voice acting does require some skill in manipulating your voice, either on your own or with technology. Voice acting is the primary reason many abridgers do their work; many of them are aspiring to be, or have become voice actors. Examples would be Takahata101, Lanipator, Semisoma1, MidnightDevont, PrinceRoy (Not an abridger, but involved with the community), and Chicknwings. There are many others as well. Some already work for larger companies, such as PrinceRoy(if you want to count being put on a waiting list as working), and some already work for smaller companies (such as Semisoma1 for LongNose Pro.), but are trying to move on to bigger ones.
Editing is a mix of video and audio editing. One example of an editor would be KaiserNeko. Although he does do voice acting, he has done numerous editing jobs in several abridged series. Editing alone, however, does not make you an abridger without either scripting or voice acting. Many Abridging editors are attempting to move on to editing careers, and using this as practice. Some abridgers outsource editing to other people, in terms of video and sound. Examples would be various series outsourcing to KaiserNeko and Ezekieru for Video editing, and numerous series (such as Yu-Gi-Oh Abridged) outsourcing SFX editing to Semsoma1. The first is much more common.
Scripting simply involves writing the script for the episodes or media, with or without other people's assistance. Regardless of voice acting or editing, anyone who does this is an abridger as soon as something they've scripted is released. Most partnership teams, such as Vegeta3986/MasakoX, have one scripter. Many larger team projects have everyone give ideas, and one person on the team fuses them together. Many other partnerships, such as Semisoma1/MidnightDevont do this as well, but on a smaller scale. In most cases, the editor is also the scriptor on teams. This is not always the case.