Wikipedia maintains a huge list of long-term abusers — "sneaky sockpuppeteers, prolific trolls, POV-pushers, and editors who add deliberately false or biased information and promotional editors." Each of the abusers has a capsule bio describing their modus operandi and area of interest.
Here are a few examples:
The Chipmunks vandal, also known as the Alvin vandal, adds trivial detail about the Chipmunks fictional musical group's cover versions to song articles, for instance adding a Chipmunks cover version to the Rolling Stones' song "(I Can't Get No) Satisfaction." Not only the Chipmunks but the vandal also targets the Chipettes and other fictional bands. He also adds trivial detail about Glee TV performances. This guy operates from various IPs in the St. Louis metropolitan area of Missouri, US.
HarveyTeenager and their socks have been known for adding hoax information about Harvey Girls Forever! coming back, as well as various hoaxes relating to Elinor Wonders Why. The primary tell is the insertion of Elinor Wonders Why into various articles and adding hoaxes related to the show (ex. adding information about a Elinor Wonders Why video game for the Nintendo Switch). Some of the information is actually true through further research, but lots are false. Also adds hoaxes involving the show's production company Shoe Ink, including a fake H2O: Just Add Water show for preschoolers. Common edits also include adding fireworks to movie plot summaries or adding fake episodes about fireworks.
Philm540 is an account that has been extremely disruptive in articles about military aircraft. In May 2015 he began to edit by way of IPv4 addresses from Pennsylvania, and then started using IPv6 addresses. His major mode of disruption is that he continually adds unreferenced information to articles. He is also insulting in his communications to others. He considers himself a respected "world-wide" topic expert, free to make pronouncements without citation, and he rejects contradictory facts found in reliable sources. He stated his real-life identity here along with the Philm540 handle. On July 1, 2015, he delivered a legal threat to a user. His interests include the air forces of the United States, various military aircraft, especially American ones from World War II, and American air units such as bombardment groups and wings.